Browse Topic: Mountings

Items (919)

Design and Analysis of a Large Hydraulic Cylinder Maintenance Device

2026-99-0214

7/31/2026

Addressing the challenges in maintaining large hydraulic cylinders and the lack of specialized equipment, this study presents a dedicated maintenance system developed through a case study of a large hydraulic lifting cylinder. Through a comprehensive analysis of maintenance requirements, we developed a six-component maintenance system comprising a foundation base, a mounting bracket, a cylinder support frame, a piston rod bracket, a drive cylinder bracket, and hydraulic components. The paper systematically explains the structural configurations and functional specifications of each component, details the operational workflow of the maintenance system, and conducts theoretical design and strength verification for critical load-bearing brackets using principles from theoretical mechanics and structural mechanics. A static analysis module from ANSYS Workbench finite element software was employed to validate the overall structure. Results demonstrate that the key components meet operational strength requirements. This innovative maintenance system proves highly feasible and serves as a valuable reference for designing similar hydraulic cylinder systems.

Qiao, Xiaodong, Du, Chao, Long, Yuheng

Rib Design of Electric Drive Unit Housings for Reduced Noise Radiation

2026-01-0687

6/20/2026

Although propulsion noise often constitutes a minority of the overall noise in electric vehicles, it remains an important quality indicator due to its high-frequency tonal character, which is undesirable even at low levels. There are many factors that influence the interior car levels of propulsion noise, i.e. gear whine and electric motor whine. The primary ones to consider are the electric drive units (EDU) internal forces, but also secondary properties such as EDU housing design and encapsulation, vehicle sound pack and mount isolation play important roles. This work focuses on EDU housing design and more particularly on the housing ribs that enables attachment point stiffness and housing strength, but which can also cause problems in terms of noise radiation. Numerical parameter studies on geometrical properties such as length dimensions, thickness and curvature were performed on single ribs of different types. For each design iteration, the key performance indicators radiated sound power, squared velocity and radiation efficiency were studied. The outcome of this work provides insights into which characteristics of ribs that are central for radiated noise. For instance, it was proven that a rather small curvature of the outer edge of a rib can decrease the radiated noise but also that certain rib dimensions can result in extensive noise due to the interaction of the first bending mode with the peak in radiation efficiency.

Lennström, David, Malm, Oskar, wurzinger, Jakob, Cederlund, Johan

An Experimental Setup for Vibroacoustic and Fluid-Born Noise Characterization of Electric Refrigerant Compressors Using R1234yf or R744

2026-01-0724

6/20/2026

The increasing electrification of vehicles means that heating, ventilation and air conditioning systems have a broader range of tasks and a different priority assessment. In electric cars, air conditioning systems are not only responsible for cooling the passenger compartment, but also for controlling the battery temperature, particularly during rapid charging, which represents a high-load operating point. Furthermore, achieving high thermodynamic efficiency is desirable, as this directly impacts the range of electric cars. The elimination of the combustion engine as a major source of noise prioritizes the noise, vibration and harshness behavior of the refrigerant compressor for product selection. To investigate the vibration and acoustic behavior, as well as the fluid dynamic forces resulting from the cyclic compression principle of an electric refrigerant compressor, a test rig was developed that allows compressors to be operated and measured in isolation in an anechoic chamber under various defined operating conditions. This test rig has been expanded in two ways within the scope of this work. Firstly, the compressor can be either rigidly attached to a dead mass using a VDA mount or measured while suspended freely. Secondly, a new R744-compatible refrigeration circuit has been added to the test rig, enabling compressors operating with the environmentally friendly refrigerant CO₂, which has so far only been used by a few manufacturers in selected models, to be tested. Measurement results obtained using this test rig provide valuable insight into the vibration behavior and sound spectra of the refrigerant compressor's fluid, structural, and airborne noise when operating at different points.

Beer, Gabriel, Saur, Lukas, Schwarz, Manuel, Zemsch, Stefan, Becker, Stefan

Vibroacoustic Analysis and Optimisation of an Electric Refrigerant Scroll Compressor

2026-01-0722

6/20/2026

In electrified vehicles, auxiliary components can represent a dominant source of noise, one of which is the refrigerant scroll compressor. Compared with vehicles equipped with internal combustion engines, electrified vehicles require larger refrigerant compressors, as thermal management is needed not only for the passenger compartment but also for the battery and electric drive components. Excitation mechanisms within the compressor, arising from the cyclic compression process and the eccentric motion of the scroll, induce housing vibrations and result in airborne sound radiation. To investigate the vibroacoustic noise generation mechanisms of a scroll compressor, operational vibrations were analysed using accelerometers and three-dimensional laser scanning vibrometry. In addition, the radiated sound was characterised using microphones and near-field sound intensity measurements. The results demonstrate a strong correlation between surface vibrations and airborne sound radiation, with the vibroacoustic behaviour being dominated by speed-dependent tonal components. Pronounced vibration and sound radiation levels occur when excitation orders coincide with rigid-body modes of the mounting system or structural eigenmodes of the compressor housing. Based on these findings, a constrained-layer damping treatment was applied to selected, highly sound-radiating regions of the compressor housing. Although the overall reduction in sound power was limited due to the high stiffness and predominantly rigid-body behaviour of the housing, local vibration and sound radiation reductions were achieved for structurally flexible components, resulting in a perceptible improvement in subjective sound quality. These results highlight the importance of spatially resolved vibroacoustic analysis for understanding noise generation mechanisms and for guiding targeted optimisation measures for refrigerant compressors.

Saur, Lukas, Beer, Gabriel, Fritzsche, Marco, Becker, Stefan

Vibro-Acoustic Simulation for Vehicle Audio Design

2026-01-0670

6/20/2026

Acoustic user interfaces and audio experiences are among the leading comfort factors in new vehicle interior designs. OEMs are more and more focusing on loudspeaker design and positioning, to provide the most immersive experience to the customers. The industrial target is to be able to predict the performance of an audio system in early design phases. This paper presents an integrated vibro-acoustic methodology enabling early-stage prediction of loudspeaker performance in real vehicle conditions. The approach combines electromechanical characterization, a hybrid loudspeaker calibrated model valid across the audible range and coupled FEM/BEM/SEA simulations to capture the loudspeaker response in the vehicle’s cabin considering door-installation effects and cabin acoustics. The method is validated experimentally on a rear-door loudspeaker installed in a production vehicle, showing strong correlation with measured SPL. A final application case demonstrates its capability to assess the impact of alternative speaker mounting positions during the design phase.

Zerrad, Mehdi, Errico, Fabrizio, Mordillat, Philippe

High-Frequency Mount Characterization: A Comparison of Methodologies

2026-01-0693

6/20/2026

The rapid electrification of the automotive industry introduces new challenges in noise, vibration, and harshness (NVH). In particular, in a virtual prototyping phase of the e-vehicles development, the rubber mounts are often one of the key elements to be considered when analysing the structure borne noise contributions. Having an accurate experimental characterization of the mount dynamic stiffness curves is therefore very relevant. However, conventional mount characterization methods are often pushed to their limits, partly due to the use of stiffer bushings, and partly because the frequency range of interest is extended toward higher frequencies. When using inverse substructuring, the dynamic stiffness curves can be obtained from frequency response function measurements. The required test setup consists of excitations and responses, located on each side of the mount via dedicated fixtures. The measured frequency response functions are reduced into 6 degrees of freedom representation at the active and passive side of the mount using the classical virtual point transformation. This classical approach assumes the fixtures to behave rigidly. This assumption holds in the lower frequency range, but not anymore in the higher frequency range. In this paper, novel approaches to identify the dynamic stiffness are presented. Namely, an enhanced virtual point transformation that considers flexible fixtures modes is proposed. Those modes may be obtained via finite element modeling or from an experimental modal analysis. Alternatively, a hybrid framework leveraging high-frequency testing and simulation to develop a parametric finite element mount model is presented. The latter approach eliminates the need for fixtures. These methodologies are compared and validated on an automotive rubber mount.

Bianciardi, Fabio, Forrier, Bart, Minervini, Domenico, Barbieri, Marco, Janssens, Karl

Design Optimization of Aircraft Light Optics: Eliminating Fasteners by Flexure-Based Clamp to Mitigate the Crack Formation and Validation through HALT

2026-26-0750

6/1/2026

Aircraft lighting systems play a vital role in ensuring operational safety, visibility, and regulatory compliance. Exterior lighting systems are essential for aircraft identification, navigation, collision avoidance, and ground operations under varying environmental conditions. These systems typically include navigation lights, anti-collision lights, landing and taxi lights. An aircraft lighting system comprises light sources, optical elements, electronic control units, power interfaces, wiring harnesses, and mechanical mounting structures. Among these components, optics are critical as they control light distribution, intensity, color accuracy, and efficiency while withstanding harsh aerospace environments such as vibration, thermal cycling, and aerodynamic loads. Aircraft exterior lights are subjected to severe thermo-mechanical stresses due to aerodynamic loading, vibration, and thermal cycling. The use of high-performance optical polymers such as Cyclo Olefin Polymers (COP) provides excellent light transmission and stability; however, their relatively lower mechanical toughness makes them susceptible to stress-induced cracking during assembly. In the baseline configuration, the Circuit Board Assembly (CBA) was fastened directly onto the optic using self-tapping screws. During assembly, frequent crack initiation was observed in the optic around the fastener locations, leading to concerns regarding reliability and maintainability. To address this issue, a redesigned mounting approach was developed that eliminated direct fastener penetration into the optic. Instead, the CBA is retained using a precision clamping mechanism, thereby distributing assembly loads uniformly and avoiding localized stress concentrations. COP material was retained due to its superior optical characteristics and compliance with photometric requirements for aircraft lighting applications. The redesigned optic-CBA interface was validated through Highly Accelerated Life Test (HALT), incorporating combined vibration, temperature, and thermal shock profiles. Test results confirmed that the new clamping design prevented crack formation, improved mechanical robustness, and ensured long-term optical performance. This paper presents the problem definition, root cause analysis of fastener-induced cracking, the design rationale for adopting a clamp-based mechanism, and detailed HALT validation results. The study highlights the importance of integrating material properties, fastening strategies, and environmental testing in the design of aerospace lighting systems. The proposed design methodology provides a pathway to enhance reliability and lifecycle performance of critical optical components in aircraft applications.

Vialta, Frederico, S, Nikhil, Katageri, Praveen, SP, Pradeep, Singh, Abhimanyu Kumar

In-situ Decoupling and Stiffness Optimization of Resiliently Coupled Assemblies Using FRF-Based Substructuring

2026-01-0227

4/7/2026

Resilient mounts are critical in controlling vibration transfer from sources such as engines, motors, and suspension to the vehicle structure. Conventional optimization methods rely on finite element analysis (FEA), which, while accurate, is computationally intensive and limits iterative NVH development. This paper introduces a Frequency Response Function Substructuring (FBS)-based approach that decomposes the system into substructures characterized by FRFs, significantly reducing computational cost without compromising accuracy. Key contributions include: (1) recovering subsystem FRFs from coupled system data in-situ for mount optimization, (2) extending FBS to handle enforced motion, and (3) proposing an alternative strategy for cases with unknown or unmeasurable loads. The methodology is demonstrated on a mid-size pickup truck model to optimize seat track response under a Four post shake load by refining body mounts. These advances broaden the applicability of FBS for efficient NVH optimization in complex systems.

Haider, Syed, Abbas, Ahmad, Jahangir, Yawar, Maddali, Ramakanth

Accelerometer Location Study for Non-Intrusive Start of Combustion (SOC) Detection in Compression-Ignition Engines

2026-01-0288

4/7/2026

This study investigates the impact of sensor location on accelerometer-based sensing of combustion phasing for compression-ignition engines. Ten accelerometer locations were studied on a light-duty compression-ignition engine for a set of conditions with variations in engine load, speed, injection timing, and injection strategy. Start of combustion (SOC) was identified from the filtered acceleration signal using a previously developed approach. Each location was assessed using both signal-based metrics, including magnitude squared coherence (MSC) between block surface acceleration and in-cylinder pressure, as well as SOC outcome-based metrics, such as detection success rate. Results demonstrate that the mounting location has a significant impact on the ability to extract combustion phasing information from the accelerometer signal. Sensors mounted on the front face of the engine produced the strongest signals for an individual cylinder. For multi-cylinder sensing, side-mounted locations delivered the most reliable performance, with SOC detection success above 98 percent, defined as correctly identifying the acceleration peak most closely aligned with the corresponding pressure-derived SOC for each cycle. This work outlines a practical framework for selecting and evaluating accelerometer mounting locations, enabling broader use of accelerometers in engine platforms operating on a range of combustion approaches.

Hegge, Graydon, Hanson, Reed, Kim, Kenneth, Rothamer, David

Multi-Stage Packaging and Routing Optimization for Automotive Component Layout, Wire Harness and Duct Route Design

2026-01-0507

4/7/2026

Modern vehicle design involves complex considerations and tradeoffs between system integration and layout which have a direct impact on performance, efficiency, and cost. The placement of equipment including control boards, motors, and fans as well as the routing of ducts and wire harnesses poses a time-consuming and intricate problem for design engineers. This paper presents an automated methodology to determine the optimal component packaging configuration, duct routing, and wire harnessing layout to maximize component packing density and minimize the total routing length. A two-stage optimization framework has been developed where the first stage packages the components within the design space with considerations for space utilization, component overlap, proximity relationships, point-to-point accessibility, and component mounting. The second stage implements a custom A* path-finding algorithm and gradient based optimization to determine the optimal route layout between port points. The objective of this work – using A* and gradient based optimization - is to minimize the total length of the duct work and harness layout while respecting proximity, overlap, and accessibility considerations. This paper outlines the methodology and real-world application through the design optimization of an automotive dashboard.

LeFrancois, Richard, Kim, Il Yong

Prediction of Dynamic Stiffness of Automotive Components Using Support Vector Methods

2026-01-5016

2/23/2026

In the current scenario of EV revolution in the automotive industry, NVH performance of the vehicles is one of the major points of sale to the customers. Auxiliary components play one of the predominant roles in the contribution of noise to overall vehicle interior or exterior sound pressure levels, which impact customer vehicle comfort. CAE prediction of NVH performance of automotive components involves a lot of design iterative processes, large server space utilization, and time-consuming. To reduce cost and time, data-driven technologies like AI algorithms can help CAE engineers because of their high efficiency and high precision. In the current research, a wiper motor mount stiffness prediction algorithm was designed based on the historical data using CAE analysis and AI algorithms, and improved prediction accuracy by tuning the parameters of AI algorithms using grid search methodology. High prediction accuracy of wiper motor mount stiffness has been achieved with the method of support vector machine. CAE engineers can avoid iterative processes by utilizing the optimized design parameters from the prediction results without running full finite element analysis simulations.

Paturi, Yuva Venkata Sekhar

Integrated architectures reshape the mobile-hydraulic ecosystem

26TOFHP02_06

2/1/2026

Off-highway equipment operates in an environment defined by extremes - extreme loads, extreme duty cycles, extreme temperatures and extreme expectations. OEMs and fleet operators face mounting pressure to deliver more power, more uptime and more precision from platforms that are becoming increasingly compact, intelligent and complex. Whether the task is hauling, lifting, dumping, clearing or moving materials, the equipment must deliver consistent, reliable performance without compromise. This pressure is reshaping the mobile-hydraulic ecosystem. The industry is steadily shifting away from piecemeal systems and toward integrated, intelligent power architectures that maximize efficiency across the entire vehicle. Leaders in this space, Eaton among them, demonstrate how a system-level approach to PTOs, hydraulic pumps and control valves is enabling a new generation of off-highway innovation.

Bogdan, Corneliu

Sound Quality Refinement and Vibration Reduction During Horn Application in Electric Vehicles

2026-26-0338

1/16/2026

This paper focuses on the cabin sound quality refinement and the tactile vibration reduction during horn application in the electric vehicle. A loud cracking sound inside the cabin and higher accelerator pedal vibration are perceived while operating the horn. Sound diagnosis is carried out to find out the frequencies causing the cracking noise. Transfer path analysis is conducted to identify the nature of noise and the predominant path through which forces transfer. Based on finding from TPA, various recommendations are evaluated which reduced the noise to a certain extent. Operational Deflection Shape (ODS) is conducted on the horn mounting bracket and on the body to identify the component having higher deflection at the identified frequencies. Recommendations like DPDS improvement on the horn bracket and the body is assessed and the effect of each outcome is discussed. With all the recommendations proposed, the cabin noise levels are reduced by ~ 8 dB (A) and the accelerator pedal vibration levels are reduced by ~ 40%. Sound quality parameter which needs to be considered during the horn selection is explained. The modal criteria which must be taken into account during development phase to avoid the horn cracking noise and tactile vibration is also proposed.

S, Nataraja Moorthy, Rao, Manchi, R, Ashwin sathya, S, THARAKESWARULU, Raghavendran, Prasath

Optimization of Propeller Shaft Design to Eliminate Launch Undulation (Lateral Shake) and Vibration Level

2026-26-0334

1/16/2026

During vehicle launches in 1st gear, a lateral shake (undulation) and a pronounced metallic hitting noise were observed in the underbody. The noise was identified as the propeller shaft's second universal joint (UJ) yoke striking the fuel tank mounting bracket. Sensitivity to these issues varied with acceleration inputs: light pedal input during a normal 1st gear launch on a flat road resulted in minimal undulation, whereas wide open throttle (WOT) conditions in 1st gear produced significant lateral shake and intensified hitting noise. Further investigation revealed that the problem persists across all gears and occurs consistently during normal driving conditions, with continuous impact between the propeller shaft yoke and the fuel tank mounting bracket. Extensive experimental measurements at the vehicle level indicated that these issues were primarily caused by the center-mounted propeller shaft joint deviating from its central position and rotating eccentrically under torque. This eccentric movement was linked to the improper propeller shaft split ratio and shorter fitting length. A detailed design study combined with vehicle-level experiments (Design of Experiments, DOE) confirmed that these factors significantly contribute to the positional shift of the second UJ connection and its resulting eccentric behavior. This study provides a comprehensive approach to addressing the issue, focusing on reducing vibrations transmitted to the floor and seats and give NVH refinement through the propeller design optimization. By doing so, it ensures improved vehicle performance without compromising other critical parameters.

Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran

Determining Optimal Suspension & Body in White Mountings to maximize Off-Road Capability of Passenger Vehicles

2026-26-0098

1/16/2026

The automotive market trend is shifting more and more to SUVs and crossovers. This, therefore, means increasing consumer demand for off-road abilities in passenger vehicles. While dedicated off-road platforms provide a path to performance robustness, getting the same level of functionality out of a passenger vehicle with minimal architectural changes proves to be a great feat for engineers. One highly critical performance determinant in the domain of off-road ability is wheel articulation, it requires independent movement capacity of the wheels to keep contact and stability over uneven terrain. Traditional articulations found in passenger car suspensions—created for comfort, packaging, and on-road dynamics—are limited by suspension geometry, damper alignment as well as compliance setup. Damper side loads- were not considered a significant factor in suspension systems that are operating within their original intended design envelope for on-road use. However, when the vehicle is taken off-road, extreme conditions lead to lateral forces during an unseated exaggerated wheel travel, these can result in seal degradation as well as rod bending increasing friction (stiction) leading ultimately to damper failure. Seal durability and general component integrity are not the only issues increased side loading will decrease articulation reduce traction and degrade ride quality during severe terrain inputs. Articulation- is essentially a measure of flexibility in the suspension which directly controls off-road performance characteristics. With limited articulation there is wheel lift traction loss and increased chassis contact. A major limitation to achieving full articulation is damper side load-the perpendicular force to the damper shaft created from angular misalignment in suspension travel. This also increases the compressive stress on the damper rod. Therefore, an optimization of the rod diameter, length, and material is required. The Ramp Travel Index (RTI) is a means of expressing articulation by using the measure of ramp height that can be attained by a vehicle climbing with one wheel while maintaining contact with others. A high RTI indicates good off-road capability. There exists an interrelationship between suspension geometry, damper side load characteristics, and axle alignment in determining off-road performance; this paper proposes an optimization guideline to overall improve wheel articulation specifically for passenger vehicles through these parameters: wheel travel, suspension hard points, and damper mounting orientations.

Siddiqui, Arshad, Iqbal, Shoaib, Dwivedi, Sushil

Adaptive Control Algorithms for Active Mounts on Diesel Powertrains in Passenger Cars

2026-26-0324

1/16/2026

Diesel powertrains are inherently characterized by high vibration levels and low-frequency excitations, which are extremely demanding for passenger comfort and vehicle refinement. Conventional passive engine mounts often fall short in mitigating such vibrations effectively across a wide range of operating conditions. Passive mounts are inadequate for effectively isolating vibrations in powerful, lightweight vehicles or those without a balancer shaft 3-cylinder engine ordiesel engines. Consequently, this has prompted the consideration of active engine mounts as an alternative solution for solving NVH (Noise, Vibration, Harshness)-related issues. This paper explores the application of adaptive control algorithms in active engine mount systems for diesel powertrains in passenger vehicles. Through the integration of real-time feedback loops with smart control strategies the system adaptively controls mount stiffness and damping to minimize engine-induced vibrations. The study presents simulation and experimental results showing enhanced vibration isolation, better ride quality, and lower transmitted forces to the vehicle chassis. In addition, the adaptive control ensures high robustness under varying driving conditions, such as load variations and engine transients. This trend opens up the future for next-generation diesel vehicle NVH solutions with a comfort-performance-fuel efficiency balance.

Hazra, Sandip, Khan, Arkadip Amitava, more, Vishwas

Value-Engineered Design Optimization of a Recycled Plastic Bracket to Meet Natural Frequency Targets in Passenger Vehicles

2026-26-0355

1/16/2026

Engine mount brackets are a primary structural components of passenger vehicles that supports the powertrain to the chassis via engine mounts. These brackets are important to control vibrations and the transmission of noise into the cabin as well as vehicle stability. Since they support the engine mounts, these brackets play a role in determining ride comfort and load distribution on the mounts and the engine. While traditionally made from steel, cast iron and aluminum, we are trying to redesign engine mount brackets with recyclable engineering plastics to fit current demands of light-weighting, cost efficiency, and sustainability. The present work is concerned with the design of a plastic engine mount bracket, which aims to hit specified natural frequency targets in order to avoid resonance and fulfill strict NVH (Noise, Vibration, and Harshness) requirements. Because of the superior mechanical strength, thermal stability, and vibration-dampening properties, PPS, glass-fiber reinforced polyamide (PA66-GF50), PEEK (polyether ether ketone), and other high-performance reinforced plastics like polyphenylene sulfide were taken into consideration. These materials can be used in structural automotive applications in place of metals. Through the Finite Element Analysis, modal analysis, CAE based durability simulations and vehicle-level testing the optimized bracket proven to meet structural and dynamic performance specifications. The findings confirm that, in the form of plastic bracket, recyclable designs can be technically feasible and sustainable alternatives to metal designs, which help reduce vehicle weight, increase fuel efficiency and vehicle manufacturability without sacrificing durability and safety.

Hazra, Sandip, Gupta, Deepak, Khan, Arkadip, Gite, Yogesh

Contradictions of Automotive NVH and TRIZ Tools for Innovative Problem Solving

2026-26-0347

1/16/2026

Balance towards various Vehicle attributes often faces design contradictions, particularly in Noise, Vibration, and Harshness (NVH) optimization. Traditional approaches rely on trade-offs, but TRIZ (Theory of Inventive Problem Solving) offers a structured methodology to resolve contradictions innovatively. This paper presents TRIZ-based solutions for 2 key NVH challenges: (1) exhaust systems requiring noise reduction while maintaining low engine back-pressure, (2) engine mounts requiring both softness for vibration isolation and hardness for durability & vehicle stability, By applying TRIZ principles such as separation, mechanics change, etc. and using Thinking Tools such as thinking in time & scale, novel solutions are proposed to achieve superior performance without traditional compromises. These case studies demonstrate how TRIZ enhances automotive NVH refinements by enabling systematic innovations. This also explores benefits of Frugal Engineering for profitable launch of new vehicles in the market without sacrifice of customer satisfaction. At the same time, new innovative solutions are generated using past-present-future prediction models.

A, Milind Ambardekar

Optimizing Rattle Behaviour in Metal-Plastic Interfaces for EV Tail Lamp Assemblies

2026-26-0332

1/16/2026

Connected tail lamps have emerged as one of the key features of modern automotive design. It aligns with current vehicle trends, giving a premium, hi-tech appearance and enhancing visibility for the drivers. (Original Equipment Manufacturers) OEM manufacturer utilizes connected tail lamps as a signature design element to establish and reinforce their brand identity. Assembly and integration of these components poses unique challenges due to Metal-to-plastic interfaces that generate audible noise such as squeak & rattle [1] and affect it affects the perceived quality of an occupant in electric vehicles (EVs). The misalignment of parts concerning geometric dimensioning and tolerancing (GD&T) specifications is addressed, as it contributes to increased micro-sliding between the interface and creates audible creaking sounds. This paper explores the influence of mounting fitment on noise generation and proposes a method to optimize the assembly process to reduce the stick-slip [2] interactions. Combining experimental testing with finite element analysis, the research focuses on identifying practical solutions by exploring mounting strategies with feasible assembly techniques [3] to prevent stick-slip interaction and improve overall perceived quality of the vehicle, for a comfortable driving experience.

Michael Stephan, Navin Estac Raja, C M, MITHUN, Mohammed, Riyazuddin, R, Prasath

An Engineering Perspective on Cradle and Saddle Mount Configurations

2026-26-0313

1/16/2026

The evolution of electric vehicles (EVs) also demands the evolution of powertrain mounting systems to achieve superior Noise, Vibration, and Harshness (NVH) performance. This study presents a comparative evaluation of cradle, saddle and ladder mounting systems in EV applications. Examples of experimental modal analysis and vehicle-level vibration tests were performed in order to evaluate structure-borne noise transmission as well as airborne noise transfer under operating conditions. Important parameters like mount stiffness, isolation efficiency and dynamic load distribution were performed. These findings provide valuable guidance for selecting optimal mount strategies to enhance occupant comfort and acoustic quality in future EV designs. Recommendations for mount system improvements considering evolving EV architectures are also discussed. This work provides a crucial, experimentally-validated framework for selecting optimal mounting architectures, addressing a key gap in the transition from ICE-based intuition to EV-specific design principles.

Hazra, Sandip, more, Vishwas, Naik, Sarang Pramod

Optimization of Electric Powertrain Mounting for Vibration Isolation in EV Powertrains Using Multibody Dynamics

2026-26-0080

1/16/2026

With growing significance of electric vehicles (EVs), their powertrains – while naturally quieter than internal combustion engine (ICE) powertrains – pose new NVH (Noise, Vibration, Harshness) challenges. These are triggered mainly from high-frequency disturbances caused by electric motors and gear interactions. Isolation of such excitations is essential for securing cabin refinement and customer expectations for acoustic comfort. This paper offers a simulation-based approach to optimal placement of the electric drive unit (EDU), which houses the electric motor and gearbox, with the objective of reducing vibration transfer to the chassis of the vehicle. The methodology explores the effect of spatial mount repositioning under actual dynamic load conditions through multibody dynamics (MBD) modeling and integrated optimizer using advanced multibody dynamics simulation software – Virtual Dynamics. The suggested workflow helps in effective investigation of mount positioning within packaging constraints, and NVH performance. Simulation analysis illustrates that optimized shifting of mount locations is capable of achieving quantifiable reductions in transmitted vibrations and dynamic response. The research showcases the potential of virtual prototyping enabling early-stage layout optimization, and outlines a feasible guide to enhance NVH performance in future EV powertrains without hardware iteration.

Shah, Swapnil, Mane, Prashant, Back, Arthur, Emran, Ashraf

Tailgate Stiffness Mitigation and Engineering Strategy for Full Width Tailgate-Mounted Tail Lamp Integration

2026-26-0494

1/16/2026

The tailgate, as the rearmost vehicle opening, plays a pivotal role in defining the rear aesthetic theme while ensuring structural durability and maximizing luggage space. Contemporary automotive design trends highlight an increasing demand for Full width tailgate-mounted tail lamp configurations, which deliver a bold and dynamic visual appeal. Enhanced by animated lighting features, these designs cater to the preferences of Gen Z customers, becoming a decisive factor in purchasing decisions. However, integrating these complex tail lamp structures introduces significant engineering challenges, including increased X-dimension lamp volume, thereby providing reduced design space, and intricate mounting schemes constrained by panel stamping limitations. These factors necessitate the development of innovative joinery strategies and structural definitions to maintain durability targets, including achieving 25,000–30,000 slam cycles without failure, while preserving luggage space. This paper presents a comprehensive design and engineering approach aimed at enhancing the modal performance of automotive tailgate systems, with a particular focus on configurations incorporating full width taillamps. The study addresses key structural challenges associated with maintaining stiffness and durability while accommodating complex styling and packaging constraints. By optimizing outer panel joinery, refining mounting strategies, and redefining inner structural reinforcements, the proposed methodology achieves significant improvements in dynamic stiffness characteristics. Experimental and simulation-based evaluations demonstrate a 12% increase in modal stiffness for conventional tailgate architectures and a 45% improvement in coupe-type liftgate configurations. The findings offer valuable insights into the co-development of structural and styling elements in modern tailgate systems, contributing to improved vehicle performance, NVH behavior, and customer satisfaction.

Beryl, Joshua, Mohanty, Abhinab, Unadkat, Siddharth, Selvan, Veera

An Investigation into the Structural Impacts of Off-Road Maneuvers on Rear Axle Upper Link Mounting Bracket

2026-26-0490

1/16/2026

Multi-link rigid axle suspension is widely used as a rear suspension system for body-on-frame SUVs. The upper link in a multi link rear suspension plays a critical role in managing the vertical and longitudinal positioning of the axle, while the lower link ensures stability by regulating the axle's movement in the horizontal plane. This coordinated functionality of upper and lower link allows for controlled axle dynamics during compression and rebound, significantly enhancing ride comfort and improving vehicle handling characteristics. This study examines the failure of an upper link mounting bracket on the rear axle of an SUV during off-road events, despite no failures observed in other durability tests. Root cause analysis is conducted on failed samples to determine the specific reasons for failure only in off-road conditions. Additionally, the investigation focuses on understanding the dynamic loads experienced by the upper link during vehicle operation across various durability tracks, identifying their contribution to the observed failure. Using Road Load Data Acquisition (RLDA) techniques, loads at the mounting bracket location are measured while running the vehicle on different terrains. The acquired data enables to understand maximum stress acting on the bracket and which terrain is worst case for the bracket failure. The study further employs the finite element method (FEM) to develop a detailed FE model of the rear axle and upper link mounting bracket. The model is subjected to measured dynamic loads to analyze stress distribution and evaluate its impact on durability. Various design proposals are explored to enhance durability and mitigate stress concentrations, aiming to prevent structural failure. Based on the analysis, the study provides design improvement recommendations to ensure reliability and robustness. These insights are vital for manufacturers striving to produce high-performance SUVs capable of enduring demanding off-road maneuvers and conditions.

J, Akhil, Senthil Raja, T, Ghumare, Dheeraj, Chilakala, Raghavendra, Kundan, Lal, Mohapatra, Durga Prasad

Packaging the HPTS Airbag in a Second-Row Seat

2026-26-0033

1/16/2026

Seats of modern cars should necessarily meet the regulatory safety norms along with aesthetics and comfort. In the existing passenger cars prevailing across the Indian subcontinent, the measure of safety has been a challenging one. The stringent regulatory norms thereby make the Airbag very promising. In the Automotive industry, safety features are very important, one of the topmost features which falls in this category is airbags. The driver and passenger safety during high impact collisions and sudden crashes is the key objective of airbag. This safety is provided by the airbag with its automatic deployment. The inflatable airbag is engineering in a way to respond very quickly during a collision and furnish necessary cushioning to decrease the impulse and enhance the safety of the passenger. The technology has been practiced widely upon many vehicles' seats. However, the present work highlights a novel approach of packaging the HPTS air bag in second row seat. This Air bag unit is fitted in the seat back frame at outboard ends of backrest. The modification is done in seat frame, foam, and trim in such a way to Airbags should be deployed in moderate to severe collisions. This study revolves around the integration and modifications in the mandatory HPTS airbag packaging requirements. This study is done to emphasize the engineering and regulatory prerequisites and their respective challenges. This study also touches on the details of mounting schemes and the evaluation of the perceived quality in implementing HPTS airbag feature on the second-row bench seat.

Buradkar, Rajat, Bose, Karthik, Jadhav, Deepika, Balakrishnan, Gangadharan

Unique Hybrid Panoramic Headliner Clip with High Tolerance to Replace Dual Lock Fasteners

2026-26-0299

1/16/2026

Mounting strategies for vehicles with panoramic sunroofs remains a challenge owing to its high complexity to balance cost, performance and assembly efficiency. Achieving efficient and reliable headliner mounting solutions is one of the conundrums where cost optimization must go together with uncompromised performance. Traditional methods like Dual Lock Fasteners (DLFs), have set high benchmarks for robustness but at the cost of increased manufacturing complexity and expense . In pursuit of a more economical and production-friendly alternative, various plastic clip designs were explored. However, these solutions posed significant challenges during validation due to the stringent requirements for mounting feasibility, tolerance management, and long-term durability This paper introduces a novel hybrid plastic-metal clip solution that addresses those challenges comprehensively. [2] The new design achieves precise tolerance control, ensuring reliable headliner installation under varying Body-in-White (BIW) conditions, while significantly improving performance metrics such as push-in and pull-out forces. Notwithstanding, the hybrid clip seamlessly fits within the existing packaging space, preserving the headliner’s aesthetics, interior headroom, and vehicle design integrity. Beyond technical improvements, this hybrid clip offers a substantial cost advantage — delivering approximately ~80% savings compared to traditional DLFs — while simplifying the assembly process and enhancing production line efficiency. Key words: Hybrid clip, DLFs- Dual lock Fasteners, BIW- Body-in-white, Headroom, Tolerance management, Mounting feasibility. [5]

D, Gowtham, Kumarasamy, Raj Ganesh, Shoeb, Mohd, Chauhan, Aarti

Machine Learning based Engine Mount NVH Life Health Monitoring System

2026-26-0359

1/16/2026

Noise, Vibration, and Harshness performance refinement and long-term vehicle reliability are rapidly evolving in today’s automotive industry and becoming a basic need considering comfort. Engine mounts play a central role in isolating powertrain-induced vibrations. Their deterioration can significantly affect cabin comfort, powertrain integrity, and customer satisfaction. Prior work in this area has primarily focused on direct mount sensors and physical inspection at service centre after failure. While effective in controlled environments, such methods are not scalable, add system complexity and increase vehicle cost due to sudden breakdowns. This paper introduces a novel indirect health monitoring method that leverages a driver seat rail-mounted accelerometer to capture driver specific vibrational responses. By analysing these signals using machine-learning models placed by AIML ECU and domain-specific analytical features, engine mount health is inferred without requiring sensors on the all three mounts. We developed and validated this approach using a combination of real-world vehicle data, controlled degradation cases, and extensive testing across varied operating conditions. Feature engineering supervised learning techniques and anomaly detection algorithms were applied to distinguish subtle variations in engine Noise Vibration and Harness behaviour at driver seat linked to mount degradation. The system demonstrated excellent predictive accuracy with reliable detection of degraded mounts without intruding on existing vehicle systems. This OEM-friendly, scalable solution enables cost-effective, real-time diagnostics and supports predictive maintenance.

Iqbal, Shoaib, Dusane, Mangesh

Research on Green and Low-Carbon Key Technology System of Tram

2025-99-0228

12/23/2025

In the context of mounting urban transportation demands, coupled with the imperatives for energy conservation and carbon reduction, incumbent tram systems confront a range of challenges. This paper proposes a green and low-carbon technological framework for tram, encompassing three phases of planning, design, construction, and operation management. It elucidates the energy-saving and environmental protection technical measures inherent in each phase, accompanied by a thorough analysis of their respective advantages and ramifications. The paper further puts forward suggestions for the green and low-carbon transformation of trams, providing both theoretical guidance and practical reference for the sustainable development of trams.

Luan, Zhi-Gang, Zhou, Hai-Zhu, Wang, Yuan-Qiao, Cai, Jing-Biao, Zhou, Li-Ning, Zheng, Liang-Ji, Tian, Jiu-Li

Uncertainty Optimization of Vibration Characteristics in Engineering Machinery Powertrain Mounting Systems Using Monte Carlo and Genetic Algorithms

10-10-01-0006

11/22/2025

With the rising demand for high performance and reliability in engineering machinery, the vibration isolation performance and robustness of the powertrain mounting system (PMS) have become critical to overall machine performance. However, during service, rubber mounts are prone to environmental influences, causing significant stiffness deviations that render traditional optimization and analysis methods inadequate. To address this, this article proposes an uncertainty optimization strategy combining Monte Carlo and genetic algorithm (MC-GA), applied to design optimization accounting for stiffness uncertainty due to mount aging, to enhance vibration isolation robustness under large-scale stiffness fluctuations. The study first establishes a Monte Carlo analysis framework based on the statistical characteristics of retired mount stiffness and a dynamic model, systematically evaluating the impact of varying stiffness deviations on vibration characteristics under the original PMS configuration. On this basis, using initial mount stiffness as the optimization variable and considering extreme aging conditions, the MC-GA method is employed for uncertainty optimization of vibration characteristics. Real-vehicle test results demonstrate the method’s strong engineering applicability: in the scenario with a 50% increase in initial stiffness, the decoupling rate improved by an average of 4.2%, effectively reducing system vibration coupling; the vibration isolation rate from chassis to powertrain in the 20–80 Hz range during operation decreased by an average of 4.3 dB, effectively reducing the vibration transmitted to the powertrain.

Xiang, Xingyu, Yi, Hongwei, Hou, Jie, Peng, Cheng, Huang, Haibo, Huang, Xiaorong

Multi-Objective Design Optimization and Pugh Matrix Analysis to Develop Exhaust Tail Pipe Mounting for EU6 Heavy Trucks

2025-28-0293

11/6/2025

The key performance evaluation criteria for any automotive exhaust system are pass-by noise (PBN), exhaust backpressure, durability and reliability, exhaust brake performance, aesthetics (if visible from outside the chassis), cost, weight and safety. Also, with changes in emission norms, emission from Exhaust Aftertreatment Systems (EATS) is one of the crucial parameters while designing the exhaust system. This paper covers a critical problem faced during the Beta Proto Build and Testing phase of exhaust tail pipe assembly. The exhaust tail pipe assembly had loose fitting issues, which can cause problems during the functioning of the truck. Parameters like material of the pipe, length of strap, tightening torque and tolerance of the pipe diameter were considered to resolve the fitment issue. The resolution is done with the help of Design of Experiments (DoE) and Pugh Matrix Analysis based on QDCFSS (Quality, Design, Cost, Feature, Safety and Sustainability). Design for Assembly (DFA) is a critical event, especially at Beta Proto Build and the pre-launch production phase. It has the dependency with design, parts (piece to piece variations- like dimension, material property), method shop floor facilities / resources (workstation – tools / machines), method/practices (variations – plant to plant / location to location) and workforces (training and physical states - like height). In the subject case, torque loosening / variations and difficulty in assembly have been reported from different plants / proto shops globally for the mounting of the exhaust tail pipe of EU6 heavy Trucks. In this context, Multi-Objective Optimization (MOO) is done with reference to DoE and Pugh Matrix evaluation to resolve the validation phase (testing) blocker problem of EU6 global trucks. Also, Quality Tools are used to do Root Cause Analysis (RCA), find Interim Corrective Action (ICA), and come up with different inputs for DoE. The primary objective of this research is to investigate and optimize the factors involved in tail pipe mounting schemes, which consist of tail pipe (GD&T and material), mounting clamp, torquing, and orientation preference. In material selection, Sustainability which is focused on SOC (substance of concern), CO2 reduction and R-Cycle framework, is equally important in decision making. This work indicates that the DoE technique, along with QDCFSS assessment, is very effective in optimizing multiple factors and resolving the problem identified by the proto build and testing team and ensuring follow the project milestone and business continuity.

P, Balu Mukesh, Rokade, Aditya, Biswas, Sanjoy

Integrating Self-Hydraulic Jacks Under the Chassis for Off-Road Vehicles, and Utility Task Vehicles

2025-28-0264

11/6/2025

A futuristic vehicle chassis rendered in precise detail using state-of-the-art CAD software like Blender, Autodesk Alias. The chassis itself is sleek, low-slung, and aerodynamic, constructed from advanced materials such as high-strength alloys or carbon-fibre composites. Its polished, brushed-metal finish not only exudes performance but also emphasizes the refined form and engineered details. Underneath this visually captivating structure, a sophisticated system of self-hydraulic jacks is seamlessly integrated. These jacks are situated adjacent to the four shock absorber mounts. These jacks are designed to lift the chassis specifically at the tyre areas, and the total vehicle, ensuring that underbody maintenance is efficient and that, in critical situations, vital adjustments or emergency lifts can be performed quickly and safely. The design also incorporates an intuitive control system where the necessary buttons are strategically placed to optimize driver convenience. Whether positioned alongside the steering wheel for immediate reach, integrated near the infotainment display for multifunctional control, or mounted within the driver's side door for easy access, these controls underscore a blend of technology and practicality.

Gogula, Venkateswarlu

Development of Test Methodology for Accelerated Fatigue Testing of Engine Pulley Bolt

2025-28-0234

11/6/2025

Engine is the prime mover of an automobile. Tractor is also equipped with engine of higher capacity to meet the power requirement. Apart from powering the wheels, engine also runs different accessories such as water pump, alternator, AC pump, Oil pump and so on. The power from the engine is transferred to accessories via chain drive or belt drive through the crankshaft pulley. During field testing, in one of the tractors, engine pulley mounting bolt failure was reported. The failure resulted in immediate seizure of the engine making the tractor standstill in the field. The root cause of the failure was unknown. Hence, there was a need to develop a component or subsystem level test methodology to address the issue quickly. In the current scope, an attempt was made to develop a subsystem level laboratory test methodology to simulate the failure mode and to validate the design modifications in an accelerated manner. The failure mode was simulated in lab and different design iterations were also tested. On successful completion of testing and implementation of the improved design, this newly developed test methodology was added as a DVP requirement to all future projects.

Chakraborty, Abhirup

Simulation Study of Wheel Bearing Friction Losses at Vehicle Level

2025-01-0399

10/7/2025

With the ongoing electrification of vehicles, components contributing a minor share of overall drivetrain losses are coming into focus. Analyzing these losses is crucial for enhancing the energy efficiency of modern vehicles and meeting the increasing demands for sustainability and extended driving range. These components include wheel bearings, whose friction losses are influenced by parameters such as temperature, mechanical loads, and mounting situation. Therefore, it is essential to analyze the resulting friction losses and their dependence on the mentioned influencing parameters at an early stage of development, both through test bench measurements and with the help of simulation models. To achieve these objectives, this submission presents a methodology that combines test bench measurements with a measurement-based simulation of the friction losses of wheel bearings occurring in the vehicle as a complete system under varying driving cycles and parameters. For this purpose, an existing complete vehicle simulation model is extended by a loss and thermal model of wheel bearings. The integrated loss model of the bearings is based on a measurement data-based loss map that takes the influencing parameters into account. The thermal behavior of the bearings is implemented in the model by using thermodynamic equations and is validated with test bench measurement data. Finally, the losses determined by using the simulation model are compared as a function of the driving cycles and the effects of influencing parameters such as environment temperature, vehicle speed and wheel load in order to quantify the impact of the boundary conditions on the friction losses. With the help of the simulation model, it is possible to quantify the influence of wheel bearing losses on overall drivetrain efficiency for various parameters in a cost- and time efficient manner. The presented methodology can also be applied to other bearings in the vehicle with slight modifications.

Hartmann, Lukas, Sturm, Axel, Henze, Roman, Notz, Fabian

2025 RISING STAR AWARDS Aerospace and Defense Winner - Keshika Warnakula

25AERP10_04

10/1/2025

Keshika Warnakula is a Senior Flight Mechanics Engineer at Syos Aerospace Limited and the winner of the 2025 Rising Stars Award Aerospace and Defense category. Syos Aerospace is based in Mount Maunganui, New Zealand, specializing in robotics engineering and the development of autonomous air, land, and sea vehicles. The company also has an office located in Fareham, UK, and was recently named New Zealand's “Hi-Tech Company Of the Year.”

Design Considerations for Wheel Bearing Outer Ring for Electric Vehicles

2025-01-0367

9/15/2025

Electric vehicles (EVs) require improved drag performance from wheel bearings to achieve a longer range. EVs are heavier and have higher torque output compared to internal combustion-powered vehicles. Due to the increased weight and torque of EVs, there will be higher loads at the bearing-to-knuckle joint. These increased loads may necessitate higher clamp loads to maintain joint integrity. However, higher clamp loads can lead to distortion or reduced roundness of the wheel bearing outer ring. Such distortion permanently increases drag and reduces bearing life. Therefore, after vehicle corner assembly with higher clamp loads, it is critical to minimize outer ring distortion during the initial assembly and throughout the bearing's lifespan. This paper will cover the design considerations for the wheel bearing outer ring to minimize distortion, utilizing Computer-Aided Engineering (CAE) analysis for various designs. A Design of Experiments (DOE) will be conducted to understand the effects of M12 versus M14 mounting bolts, assembly stiffness, outer ring mounting area, knuckle bolt pitch circle diameter (PCD), concavity, and bearing outer ring flange thickness. A second DOE will investigate the non-linear effects of the strongest factors identified in the initial study.

Mandhadi, Chaitanya Reddy, Callaghan, Kevin, Sutherlin, Robert, Lee, Seungpyo, Lee, Yeonsik, Bovee, Benjamin

Mitigating High Steering Effort in Power Steering Pumps through Manufacturing Process Improvement

02-19-01-0003

8/1/2025

Power steering pumps are the heart of any hydraulic power steering system. They provide the heavy lifting power required in the form of high-pressure fluid flow that is utilized in powered steering gears or steering racks to assist drivers in vehicle maneuvers, specifically in low-speed situations. Failure of the power steering pump will inevitably increase work needed from the driver to steer a vehicle and decrease the driver comfort at the same time. This article covers investigations into a customer return issue, affecting more than 20% of pumps, for one particular failure mode, pump input shaft seal leakage, and how the failure is not caused by failure at the input shaft nor by failure of the input shaft seal. It was found that internal damage to the pump rotating assembly allows high-pressure oil to overcome the input shaft seal sealing effect. The cause of the failure was determined to be rooted in the manufacturing process, which was re-ordered to reduce the failure rate to an acceptable value (<1%).

Bari, Praful Rajendra, Kintner, Jason

Balancing Machines: Tooling Design Criteria

ARP4163A (Current)

7/9/2025

This document establishes general design criteria, tolerances, and limits of application for tooling, fixtures, and accessories for mounting and driving gas turbine engine rotors on horizontal and vertical balancing machines.

EG-1A Balancing Committee

Noise Management in Electric Vehicle Compressors for Superior Cabin Comfort

2025-01-0191

6/16/2025

This research addresses the issue of noise, vibration, and harshness (NVH) in electric buses, which can hinder their widespread adoption despite their environmental benefits. With the absence of traditional engines, NVH control in electric vehicles focuses on auxiliary components like the air compressor. In this study, the air compressor was identified as a major source of vibration, causing harsh contact between its oil sumps and mounting bracket. Analyzing the vibrations revealed that the sump and bracket were not moving freely, increasing noise. Modifying the bracket design to allow more movement between the components successfully reduced both noise and vibration. The paper details the experimental process, findings, and structural damping methods to mitigate NVH in electric buses.

Paroche, Sonu, Patel, Shubhanshi, Patidar, Ashok Kumar

Numerical Simulation and Parametric Optimization of Engine/Powertrain Mounts: Identifying Key Design Variables to Reduce NVH Noise

2025-01-0251

6/16/2025

Engine and powertrain mounts are vital for isolating vibrations and reducing the transmission of Noise, Vibration, and Harshness (NVH) from the engine to the vehicle structure. Despite technological advancements, addressing NVH issues related to tribological factors continues to pose significant challenges in automotive engineering. This study aims to systematically identify and optimize design parameters of engine/powertrain mounts to minimize NVH levels using CAE tools and parametric optimization techniques in Abaqus and Isight, respectively. The purpose of this research is to investigate the correlation between various design parameters of powertrain mounts and their impact on NVH characteristics. Specific attention is focused on noises such as clunking, banging, or thumping that emerge from the engine bay under dynamic conditions like acceleration, braking, or turning. These sounds often occur as the engine moves excessively due to worn mounts, making unintended contact with other components and producing impact noises. This study explores these interactions, with a particular emphasis on tribological factors within the mount systems. The research utilizes Abaqus for detailed finite element simulations to model the dynamic behavior of engine mounts under operational loads. Isight is used for parametric optimization, where key variables such as mount geometry, stiffness, damping properties, and material specifications are adjusted. A multi-objective optimization function is developed to find an optimal balance between reducing NVH levels and ensuring mount durability and performance. The study includes a sensitivity analysis to prioritize the most impactful design variables, followed by optimization algorithms to refine the mount design for optimal NVH mitigation.

Ganesan, Karthikeyan, Seok, Sang Ho

NVH Improvement of the BEV Transmission by Altering Bearing Mounting Arrangement

2025-01-0104

5/5/2025

As per metaphor, “The squeaky wheel gets the grease,” and in the case of Battery Electric Vehicles (BEVs), the transmission system has become the focal point for NVH (Noise, Vibration, and Harshness) improvements. With the engine being replaced by the near-silent electric motor, the noise generated by the transmission has become more prominent, demanding greater attention to noise reduction. This shift has created a pressing need for innovations in both design and manufacturing processes to enhance the overall quietness of the vehicle. As a result, ongoing advancements are being made to address and improve the NVH characteristics of BEV transmissions. Following paper will discuss the improvement in NVH achieved through a design innovation in the way bearings are installed and demonstrated a significant amount of improvement. We have used SMT MASTA as a simulation tool to predict the expected results and a Transmission Dyno test bench in an anechoic chamber to test the NVH performance on physical sample. The innovation was done on a small single speed two stage reduction gearbox coupled with a 100 Nm, 14000 RPM battery electric motor. While bearings may seem to have a minor influence on overall NVH, their role in transmitting reaction forces to the housing is critical. By innovatively altering this transmission mechanism, we’ve significantly reduced transmission error (TE), gear misalignment, and vibrations, as predicted by advanced gear simulation tools like MASTA. Rigorous testing of the prototype in an anechoic chamber confirmed these predictions, resulting in a notable 2 to 6 dB(A) reduction in NVH. Additionally, this innovative bearing arrangement optimizes bearing wear and extends the overall duty cycle. By redistributing axial and radial forces, we’ve achieved a 25% reduction in damage for a given duty cycle, or equivalently, a significant increase in lifespan while maintaining the original performance level.

Pingale, Abhijeet, Soni, Jaldeep

Effects of Acoustic Dissipative Material in Applications with Acoustic Leakage

2025-01-0117

5/5/2025

This paper investigates the performance of a dissipative material compared to conventional acoustic materials under conditions that simulate real-world vehicle applications with acoustic leakage. Various acoustic materials were evaluated through laboratory experiments, which included acoustic leakage in both the steel panel and the acoustic materials. Acoustic leakages commonly occur in actual vehicle conditions at pass-throughs or fastener mounting locations. The study also presents in-vehicle test results to demonstrate the effectiveness of the dissipative material in managing acoustic leakage.

Yoo, Taewook, Maeda, Hirotsugu, Sawamoto, Keisuke, Anderson, Brian, Gan, KimTong, Herdtle, Thomas

Asymmetric Gear Blank Optimization to Reduce Gear Noise for Electric Drive Units

2025-01-0079

5/5/2025

Gear whine has emerged as a significant challenge for electric vehicles (EVs) in the absence of engine masking noise. The demand from customers for premium EVs with high speed and high torque density introduces additional NVH risks. Conventional gear design strategies to reduce the pitch-line velocity and increase contact ratio may impact EV torque capacitor or its efficiency. Furthermore, microgeometry optimization has limited design space to reduce gear noise over a wide range of torque loads. This paper presents a comprehensive investigation into the optimization of transfer gear blanks in a single-speed two-stage FDW electric drive unit (EDU) with the objective of reducing both mass and noise. A detailed multi-body dynamics (MBD) model is constructed for the entire EDU system using a finite-element-based time-domain solver. This investigation focuses on the analysis and optimization of asymmetric gear blank design features with three-slot patterns. A design-of-experiment (DOE) methodology is employed to identify pivotal gear blank design parameters, including the blank thickness and slot angle. The radiated sound power and mount vibration responses from the EDU are predicted and correlated with test data. The time-varying stiffness at the meshing point gives rise to sidebands around the transfer gear orders, which are accurately captured using the MBD time-domain solver. The asymmetric gear blank stiffness changes the torsional vibration transfer path, necessitating microgeometry re-optimization to fully capture the NVH benefits. A case study is conducted based on the Ultium EDU, focusing on transfer gear blank design. It is demonstrated that a selected three-slotted gear blank design, in conjunction with optimized microgeometry, results in reduced mass and up to 10 dB lower gear noise for the electric drive unit system.

He, Song, Bahk, Cheonjae, Li, Bo, Du, Isaac, Patruni, Pavan Kumar, Baladhandapani, Dhanasekar

Road Noise Analysis using Component TPA and FBS with Vehicle Component Modifications

2025-01-0055

5/5/2025

Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and rubber bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this process, analytic springs were added in parallel to the actual rubber mounts, which were also measured using VPT on the actual vehicle. These springs simulate positive or negative changes in stiffness, allowing the study of how changes in the rubber mounts affect the vehicle's NVH performance. In this study, a sensitivity analysis was conducted using the FBS model to observe changes in road noise resulting from variations in bushing stiffness and blocked force. Based on the results of this analysis, the optimal combination of components was proposed for reducing the road noise. This approach provides an efficient and accurate method for analyzing the effects of rubber mount modifications on NVH performance.

Kim, Jungu, Reichart, Ron, de Klerk, Dennis, Schütler, Willem, Malic, Mario, Kim, Hyeongjun, Kim, Uije

ARP5481A (Current)

4/14/2025

This SAE Aerospace Recommended Practice (ARP) provides the recommended procedure for obtaining desired preloads in aircraft wheel tie bolts when mounting tires and assembling the wheel. It is generally referred to as the snug-angle bolted joint assembly procedure. It is also known as the “torque-turn” procedure in the heavy equipment ground vehicle industry.

A-5A Wheels, Brakes and Skid Controls Committee

Headliner Design Considerations to Meet Safety and Regulations

2025-01-8245

4/1/2025

Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface, its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc which are fitted on the headliner does not get detached or break off, which in turn can be dangerous to the occupants. The design of pillar trims and the ramp bracket also plays a critical role in ensuring that the pillar trim edges are secure during the airbag deployment, and aid in the easy release of airbag into the cabin. Incorrect design of headliner or pillar trim, can result in different problems such as improper airbag deployment, airbag getting struck between pillar trim to body, fly-off of headliner child parts, etc. This would also result in several iterations of design which is a waste of time and resources. In this paper, we cover various design aspects of headliner assembly to meet the safety and regulations and have an improved deployment of curtain airbag. By considering the design aspects upfront, we were able to save at least two iterations of air bag deployment and quicken the development time by four months.

Sabesan, Arvind Kochi, D., Anantha, Kakani, Phani Kumar

Single-Shot Polarization Imaging System Provides Complete Picture

TBMG-52816

4/1/2025

Companies have invested heavily to improve color in digital imaging, but wavelength is just one property of light. Polarization — how the electric field oscillates as light propagates — is also rich with information, but polarization imaging remains mostly confined to table-top laboratory settings, relying on traditional optics such as waveplates and polarizers on bulky rotational mounts.

Optimization Method for Powertrain Mounting Systems Based on Enhanced Genetic Algorithms

2025-01-8644

4/1/2025

A methodology for optimizing natural properties of a powertrain for an electric vehicle has been presented. A model with six-degree-of-freedom was proposed utilizing ADAMS, and the natural frequencies and energy distribution of the powertrain are estimated using the proposed model. The calculated natural frequencies and energy distribution shown that the initial design of mount stiffness does not meet requirements of natural frequency and decoupling ratio, and vibration isolation standards. To overcome the limitations of conventional optimization techniques, a non-dominated sorting genetic algorithm (NSGA) was adopted for the enhancement optimization the mounts parameters. The optimization objectives included the refinement of the decoupling rates and frequency distribution at all mounting directions. Stiffness parameters of the mounts were optimized via the NSGA. The optimized results confirmed significant improvements for powertrain natural characteristics. This study presented an effective optimization approach for design of electric vehicle powertrain mounting systems.

Jin, Yang, Li, Dewei, Zhao, Yang, Xiao, Lei, Guo, Yiming

Integrated Bracket Design Optimizations to Resolve Issues in Vehicle Prototype Stage

2025-01-8614

4/1/2025

The integrated bracket is a plastic part that packages functional components such as the ADAS (Advanced Driver Assistance System) camera, rain light sensor, and the mounting provisions of the auto-dimming IRVM (Inner Rear View Mirror). This part is fixed on the windshield of an automobile using double-sided adhesive tapes and glue. ADAS, rain light sensors, and auto-dimming IRVM play an important part in the safety of the driver and everyone present in the automobile. This makes proper functioning of the integrated bracket very integral to occupant safety. Prior to this work, the following literature; Integrated Bracket for Rain Light Sensor/ADAS/Auto-Dimming IRVM with provision of mounting for Aesthetic Cover [1] outlines the design considerations and advantages of mounting several components on the same bracket. It follows the theme where the authors first define the components packaged on the integrated bracket and then the advantages of packaging multiple components on a single bracket. However, it fails to showcase the development phase of the part. In this paper, the authors take the readers through a set of issues faced in the development phase of integrated bracket. The development phase is the phase when tooled-up parts arrive at the manufacturing plant and get assembled on the vehicle. During this phase, issues at the part level and assembly level are addressed by respective engineering teams. The issue resolution comprises three main parts: root cause analysis, immediate corrective action, and permanent corrective action. Root cause analysis is where the cause is identified. Immediate corrective action is a temporary solution to the problem that can be implemented on day one without any lead time. Permanent corrective action is the final stage of issue resolution where the improved parts start arriving at the manufacturing plant after tool modification.

Chandravanshi, Priyansh, Dharmatti, Girish

A Study on Powertrain Modes for Optimizing the NVH Performance

2024-28-0187

12/5/2024

The stiffness and positioning of engine mounts are crucial in determining the powertrain rigid body modes and kinetic energy distribution. Therefore, optimizing these mounts is essential in the automotive industry to separate the torque roll axis (TRA) and minimize vibration. This study aims to enhance mount locations by isolating the engine rigid body modes and predicting the inter-component force (ICF) and transfer function of the vehicle. The individual ICFs for engine mountings are calculated by applying a unit force at the bearing location. Critical frequencies are identified where the amplification exceeds the unit force at the mounting interface between the engine and the frame. The transfer function approach is utilized to assess the vibration at the handlebar. Both ICF and transfer functions analyze the source and path characteristics linked to critical response frequencies. This understanding aids in enhancing mounting positions to minimize vibration levels, thereby enhancing NVH performance.

Jha, Niraj Kumar, Yeezaku, Antony Neomin, Victor, Priyanka Esther, Krishnamurthy, Govindasamy

“Smart Testing Methodology for Air Suspension System of Buses”

2024-28-0201

12/5/2024

In the fast growing automotive sector, reliability & durability are two terms of utmost importance along with weight and cost optimization. Therefore it is important to explore new technology which has less weight, low manufacturing cost and better strength. It also seek for a quick, cost effective and reliable methodology for its design validation so that any modification can be made by identifying the failures. This paper presents the rig level real world usage pattern simulation methodology to validate and correlate the vehicle level targets for micro strain, wheel forces and displacement on suspension components like optimized Z spring, torque rods, pan hard rod & mounting brackets of newly developed air suspension for buses.

Tangade, Atul Bandu, Babar, Sunil, Bankar, Milind Achyutrao, Mehendale, Ravindra, Dhumal, Kailas, Bhusari, Deepak, Sonawane, Ravindra, Shinde, Saurabh

These Speedy Cold Spray Machines Can 3D Print Vehicle Parts in War Zones

24AERP12_04

12/1/2024

As “point of need” additive manufacturing emerges as a priority for the Department of Defense (DoD), Australian 3D printing provider SPEE3D is one of several companies demonstrating that its machines can rapidly produce castings, brackets, valves, mountings and other common replacement parts and devices that warfighters often need in an on-demand schedule when deployed near or directly within combat zones. DoD officials describe point of need manufacturing as a concept of operations where infantry and squadron have the equipment, machines, tools and processes to rapidly 3D print parts and devices that are being used in combat. Based in Melbourne, Australia, SPEE3D provides cold spray additive manufacturing (CSAM) machines that use a combination of robotics and high-speed kinetic energy to assemble and quickly bind metal together into 3D-printed parts without the need for specific environmental conditions or post-assembly cooling or temperature requirements. Over the last two years, the company has participated in military point of need manufacturing challenges and demonstrations with military units from the U.S., UK, Australia and Japan among others.

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