Browse Topic: Vibration

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Mechanical Boom Vibration Mitigation using Active Force Control2025-28-0345To be published on 11/06/2025
In off-highway vehicles, an undesirable vibration in a mechanical structure is a well-known problem. Such vibrations are discomforting in humans and can even lead to serious health issues related to orthopedics. Passive vibration attenuation approaches are popular in engineering practice but rely heavily on vehicle structural changes. Moreover, such approaches are known to be less effective on low frequency vibrations. In the last decade or so, there has been significant technological advancement in actuators as well as sensing mechanisms. This has enabled us to realize active vibration control as an important tool in managing excessive vibration levels. It is noteworthy that a typical active vibration control assumption is that the controlled structure maintains its dynamic properties throughout the control procedure. This simplifies linear-time invariant (LTI) model-based control design approaches. We note that in certain applications, such as gantry cranes, spraying mechanical booms
Patil, Bhagyesh, Bawankar, Shubham
Isolation of Engine Vibrations from 3 Cylinder Engines on Off-Highway Machines2025-28-0292To be published on 11/06/2025
The BS4 regulation for emission required several changes on engines as well as design and development of new auxiliary systems. These changes affected the engine dynamic behavior and ultimately noise and vibration in engine. These changes are validated for various operating conditions on engine test cell in a controlled environment where engine is mounted on test cell with dyno. Further, this engine is used in various equipment application and needs to be validated for noise and vibration performance. Three-cylinder engines have inherent imbalance forces, hence it is extremely critical to select the proper engine isolators to reduce the vibrations and noise. This paper covers the methods used for verification of engine isolation performance. NVH tests are conducted for integration of three-cylinder engine with roadbuilding machine. An analytical model is developed to identify rigid body modes and mount transmissibility. Results from this analytical model were verified with a physical
Pawar, Sachin M., Mandke, Devendra Laxmikant, KASABE, SANDEEP, Jadhav, Vijay
Order Dispersion Method by Crankpin Arrangement into Enhancements of Structural Reliability and Sound Quality for V8 Outboard Motor2025-32-0021To be published on 11/03/2025
This paper provides insight into the utility of the low vibration crankshaft for outboard motors, especially focuses on the enhancements of the structural reliability of the crankshaft and the sound quality of the outboard motor. In previous research, we developed the crankshaft which can balance by itself for V8 outboard motor with V bank angle of 60 degrees. We specifically showed the theoretical basis of the balancing and the measurement results of actual vibration levels on boat. Meanwhile, note that the crankshaft has a distinctive structure of crankpin offset angle of 60 degrees, so that combustion interval becomes unequal. As to the combustion, however, we just mentioned the effects on the engine output performance, not the practicality. In this paper, we clarify the following two benefits of unequal interval combustion in terms of the structural reliability and the sound quality. One is that the order dispersion resulting from unequal interval combustion can reduce the
Takanishi, Kentaro, Muramatsu, Hideta, Kondo, Takashi, Naoe, Gaku
Noise mitigation techniques in vehicle HVAC system2025-28-0378To be published on 10/30/2025
Noise produced by Heating, Ventilation, and Air Conditioning (HVAC) systems in automobiles considerably influences passenger comfort and the overall driving experience. As automotive manufacturers strive to improve the acoustic environment within vehicles, the reduction of HVAC system noise has emerged as a significant concern. The main sources of noise in HVAC systems consist of fan operation, compressor vibrations, and airflow turbulence occurring within ducts. This paper investigates several technical strategies to diminish HVAC system noise, emphasizing advanced methods such as Campbell diagrams, waterfall charts, and techniques for system optimization One significant approach for noise mitigation is the utilization of Campbell diagrams, which serve as essential instruments for pinpointing resonant frequencies in HVAC components. By graphing frequency in relation to rotational speed, engineers are able to identify critical resonance points and devise solutions to either avoid or
Trivedi, Arpita, Kumar, Ravi, Madaan, Ashish, Shrivastava, Pawan
DESIGN AND DEVELOPMENT OF FIBER OPTIC VIBRATION SENSOR FOR AUTOMOBILE APPLICATIONS2025-28-0371To be published on 10/30/2025
Fiber optic sensors are impervious to EMI, which makes them ideal for usage in high-EMI settings like automotive and aerospace applications. These problems might result in expensive repairs and less comfortable driving if they are not fixed right away. In order to lessen this, fiber optic vibration sensors have been developed as a way to detect and analyze vibrations produced by automobile systems by detecting and observing changes in transmitted optical signals. These sensors, which are usually based on fiber optic technology, allow for real-time condition monitoring of the vehicle. Unusual vibration patterns can be identified by installing these sensors in crucial parts like the engine block, gearbox, suspension, or wheels. This allows for early diagnosis and preventative measures. In addition to preventing major malfunctions, this finite element analysis technique increases fuel economy, boosts driver comfort, and guarantees the vehicle’s general dependability. A major development
P, Geetha, Koppala, Neelima, Nagarajan, Sudarson
Efficient Simulation Methodology for Caliper Rattle Noise Based on a Reasonably Simplified Model and Integrated NVH CAE Approach2025-01-0348To be published on 09/15/2025
Brake caliper rattle noise is difficult to simulate due to its non-stationary, random, and broadband frequency characteristics. Many CAE engineers have adopted rattle vibration as an alternative metric to quantitative noise levels. Previous rattle noise simulations primarily presented relative displacement results derived from normal mode analysis or vibration dB levels rather than actual noise dB levels. However, rattle noise consists of continuous impact noise, which must account for reflections, diffractions, and refractions caused by transient nonlinear contacts and localized vibrations—especially during extremely short contact events. To accurately simulate impact noise, vibration and acoustic characteristics should be analyzed using a simplified structure, given the numerous mechanisms influencing impact noise generation. The rattle noise can be effectively modeled using LS-Dyna, which incorporates both explicit and BEM solvers. The correlation between test results and CAE
Park, Joosang
Active–Passive Torsional Vibration Suppression Method for Electromechanical Coupling System of Parallel Hybrid Electric Vehicles10-09-04-003408/21/2025
The diversity of excitation sources and operating modes in hybrid electric vehicles (HEVs) exacerbates the torsional vibration issues, presenting significant challenges to the vehicle’s overall noise, vibration, and harshness performance. To address the complex torsional vibration challenges of the HEVs, this study proposed an active–passive collaborative vibration suppression approach. In terms of passive suppression, a multi-condition parameter optimization scheme for the torsional vibration dampers is designed. In terms of active suppression, a fuzzy control–based electronically controlled damper is proposed, and a hybrid feedforward–feedback motor torque compensation strategy is developed. Simulation results demonstrated that the proposed method reduces the root mean square value of the angular acceleration by over 65% under acceleration and idle conditions and the maximum transient vibration value by 55% during the engine starting condition.
Yan, Zhengfeng, Liu, Shaofei, Huang, Tianyu, Zhong, Biqing, Bai, Xianxu, Huang, Yin
Shimmy Analysis of Differential Steering-by-Wire System for Electric Vehicles with In-Wheel Motors and Steering Trapezoidal Mechanism2025-01-504907/15/2025
The differential steering-by-wire (DSBW) system eliminates the need for steering gear, i.e., rack and pinion, while preserving a trapezoidal steering structure with knuckles. This design offers significant advantages for vehicles equipped with in-wheel motors, primarily due to reduced vehicle weight and the maintenance of front wheel alignment parameters. However, the noise force acting on one steering wheel will directly transmit to the other in this differential steering mechanism due to a lack of mechanical connection to the vehicle body through the steering gear, which increases the risk of steering wheel shimmy (SWS). This article qualitatively analyzes the shimmy characteristics of the steering wheel based on a three-degrees-of-freedom (3-DOF) DSBW shimmy model established using Lagrange’s equation and the Hopf bifurcation theorem. The results indicate the vehicle range that this steering system will shimmy, and the maximum steady amplitude is [4.80 m/s, 31.57 m/s] and 0.1516 rad
Zhao, Huiyong, Liang, Guocai, Wang, Baohua, Feng, Ying
Optimisation of Rotor Skewing of a Yokeless and Segmented Armature Axial Flux Machine2025-01-031107/02/2025
This paper presents an optimisation approach for rotor skewing in a Yokeless and Segmented Armature (YASA) design Axial Flux Machine (AFM) for electric vehicle applications. Torque ripple amplitudes are a critical factor influencing the noise, vibration and harshness (NVH) behaviour of electric motors. The focus of this paper is to reduce the torque ripple amplitudes of the dominant harmonics over the entire torque-speed characteristic of the AFM. The principle of the proposed approach is a segmented permanent magnet configuration of the AFM, where individual magnet segments can be circumferentially shifted to achieve optimal skewing configurations. Initial optimisations are performed using 2D finite element (FE) simulations, modelled as linear motors with multiple slices and different numbers of magnet segmentation. However, the accuracy of the 2D FE results is limited due to the lack of interaction between the individual segments and the insufficient representation of three
Müller, Karsten, Maisch, Hannes, De Gersem, Herbert, Burkhardt, Yves
Evaluation of Static and Dynamic Stiffness of Rubber Grommet by Experimental and FEA Method2025-01-027407/02/2025
Vibration control is most important in automotive applications, and generally, rubbers are used to dampen these vibrations due to their inherent nature and low-cost manufacturing methods. Now, to select a rubber material, Shore hardness is considered in engineering applications, but to additionally control the behaviour, we need to understand its static and dynamic stiffness. These values help to determine the vibration isolation obtained by these rubbers. In this paper, we will discuss methods to calculate the static and dynamic stiffness of rubber grommets using experimental methods and FEA modelling. As elastomers have non-linear material properties, various material modelling techniques in FEA are used to capture multiple phenomena like creep, fatigue, and dynamic conditions. Rubber compounding is used in order to improve the physical and chemical properties, which in turn would give desirable linear characteristics. Certain guidelines and thumb rules are used in the rubber
Khamkar, Prasad Subhash, Gaikwad, Vikrant Chandrakant
Road Noise Improvement Method for Battery Electric Vehicles Based on Bushing Stiffness Optimization10-09-04-003206/23/2025
The chassis bushing is one of the key components affecting the vibration isolation efficiency of a vehicle, and a comprehensive optimization method combining the experimental process and transmission path analysis (TPA) is proposed to reduce the low- and medium-frequency road noise response in the passenger compartment of a battery electric vehicle (BEV). First, the noise signals were obtained in the vehicle road noise test under two working conditions of 40 and 60 km/h at uniform speeds on rough road surfaces. Then, the excitation transmission path was analyzed based on the structural noise transmission model, and the chassis bushing parts with more considerable vibration isolation contribution were screened out. By matching the stiffness values of the chassis bushings in the optimization problem through experimental methods, the optimization scheme reduces the stiffness of the front swing arm bushing and the rear longitudinal arm bushing by 30%. Additionally, a flexible connection is
Liu, Ke, Liao, Yinghua, Wang, Hongrui, Zhou, Junchao
Noise Management in Electric Vehicle Compressors for Superior Cabin Comfort2025-01-019106/16/2025
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
NVH Improvement of Transmission Electric Oil Pump with Uneven Pitch Control2025-01-025206/16/2025
This paper proposes an uneven pitch control for electric oil pumps. For the noise reduction of vane pumps, mechanical arrangements of uneven pitch vain angle are widely used. However, the tooth angle of gear-type pumps should be even mechanically. The proposed uneven pitch control provides similar effects of the mechanical uneven pitch arrangement by instantaneous motor torque controls of the electric oil pump which cannot have uneven pitch mechanically. The magnitude of motor torque for each pump tooth is determined by an uneven pitch formula which is widely used for mechanical vane pumps in previous study and patents. A formula for the shape of motor torque is proposed by analyzing pressure fluctuations of pump as a combination of trigonometric and exponential functions. The calibration factors for the magnitude and shape are adjusted by characteristics of pumps. The experimental results showed that noise reduction and dispersion effects of the proposed method.
Choi, Chinchul, Kim, Jongbeom
2025 Ford Expedition: New friendly features and a Tremor for legit off-roading25AUTP06_1506/01/2025
Ford has engineered the 2025 Expedition with an eye to putting it at the top of the large SUV class in which it has usually been a contender. With loads of tech that works well and is controlled easily, friendly features and a highly capable new Tremor off-road edition, it offers plenty of justifications for its pricing. SAE Media was hosted by Ford in Louisville, Kentucky, for a drive of various Expedition trim levels, including a first-hand view of the Tremor's off-road prowess. Among the useful features is the new Split Gate, of which the top 75% lifts like a traditional SUV liftgate. The utility comes in with the lower 25%, which drops like a truck tailgate and can support up to 500 pounds for your football tailgating or other purposes. And avoiding a potential user annoyance is available Open-on-Approach, which opens both gate portions by merely standing near the back of the Expedition. The design of the upper part of the Split Gate, by the way, evokes the apocryphal quote from
Clonts, Chris
Leveraging Vision Language Models and Prompt Engineering for Bearing Defect Classification from Vibration Signals2025-01-012705/05/2025
Bearings are fundamental components in automotive systems, ensuring smooth operation, efficiency, and longevity. They are widely used in various automotive systems such as wheel hubs, transmissions, engines, steering systems etc. Early detection of bearing defects during End-of-Line (EOL) testing and operational phases is crucial for preventive maintenance, thereby preventing system malfunctions. In the era of Industry 4.0, vibrational, accelerometer, and other IoT sensors are actively engaged in capturing performance data and identifying defects. These sensors generate vast amounts of data, enabling the development of advanced data-driven applications and leveraging deep learning models. While deep learning approaches have shown promising results in bearing fault diagnosis, they often require extensive data, complex model architectures, and specialized hardware. This study proposes a novel method leveraging the capabilities of Vision Language Models (VLMs) and Large Language Models
Chandrasekaran, Balaji, Cury, Rudoniel
Sound Quality Centered Measurement Technique over 40+ Years: Experiences and Perspectives2025-01-007305/05/2025
The author’s life work in acoustics and sound quality, continuous over more than 40 years, has followed a number of branches all involving measurement technologies and their evolution. The illustrated discussion begins 60 years ago in 1965 at Arizona State University in its Frank Lloyd Wright-designed Gammage Auditorium, and moves to the Research and Development Division of Kimball International, Inc. (Jasper, Indiana) in 1976 with piano research using a Federal Scientific Ubiquitous analog real-time FFT analyzer and Chladni-plate-mode studies with fine sand and high-speed photography of sound board modes. It continues at Jaffe Acoustics, Inc., a concert-hall-specializing consultancy in Norwalk, CT, with early-reflection plotting using a parabolic microphone on an altazimuth angular-readout mounting and either photographing oscillograms, or running a high-speed paper chart printer, assembling “wheel plots” incremented every 10 degrees in azimuth and altitude to map reflection patterns
Bray, Wade
The Applications of Acoustic Black Holes to Attenuation of Coach/Bus Frame Structure Vibrations2025-01-006505/05/2025
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB
Xu, Chuanyan, Wang, Jianjun, Xing, Qisen, Chen, Hengbin, Huang, Xianli
Road Noise Analysis using Component TPA and FBS with Vehicle Component Modifications2025-01-005505/05/2025
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
Kim, Jungu, Reichart, Ron, de Klerk, Dennis, Schütler, Willem, Malic, Mario, Kim, Hyeongjun, Kim, Uije
100+ Years of Noise and Vibration in the Auto Industry2025-01-007105/05/2025
Over the past 30 years concerns about noise & vibration have become more critical in the design and manufacture of the automobile. Tools, both in physical testing and computer aided engineering have and continue to develop permitting more refined designs. Today’s customer can be very discerning when it comes to vehicle noises and vibrations. However, this is not a new concern for automotive customers or manufactures. This paper highlights the drive from automotive manufacturers to promote quiet, smooth and vibrationless operation of their products as well as some of the advances in vehicle component design over the past 100+ years. This is not an exhaustive study, but rather the intent is to bring to light the long history of noise and vibration in the automotive industry and its importance to the customers even in the infancy of the auto industry.
Kach, Raymond, Thompson, James
Global Vehicle Vibration Enhancement Using Circular Force Technology2025-01-001505/05/2025
In addition to providing safety advantages, sound and vibration are being utilized to enhance the driver experience in Battery Electric Vehicles (BEVs). There's growing interest and investment in using both interior and exterior sounds for pedestrian safety, driver awareness, and unique brand recognition. Several automakers are also using audio to simulate virtual gear shifting of automatic and manual transmissions in BEVs. According to several automotive industry articles and market research, the audio enhancements alone, without the vibration that drivers are accustomed to when operating combustion engine vehicles, are not sufficient to meet the engagement, excitement, and emotion that driving enthusiasts expect. In this paper, we introduce the use of new automotive, high-force, compact, light-weight circular force generators for providing the vibration element that is lacking in BEVs. The technology was developed originally for vibration reduction/control in aerospace applications
Norris, Mark A., Orzechowski, Jeffrey, Sanderson, Brad, Swanson, Douglas, Vantimmeren, Andrew
A Study on the Subwoofer Rattle Noise Analysis and System Target Setting2025-01-009005/05/2025
Rattling noise from electrical sound systems is becoming one of the prominent issues for automakers as it directly affects the perception of customers about vehicle quality. Recently, quality sound system is prerequisite for automotive passenger vehicles. And, in the whole systems subwoofer forms dominant part of sound output. However, subwoofer rattle noise problems sometimes occur in small and midsize Sports Utility Vehicles (SUV). Mainly rattle is noise resulting from physical contact of two parts due to vibrations when relative displacement is bigger than gap of two parts, it occurred certain frequency (Between F1~F2), which is main excitation range of subwoofer. In this study, we analyze the subwoofer structural vibration analysis for five sample vehicles based on the test and correlation. However, the present subwoofer system model has limitation in determining the level of this rattle noise. Therefore, this paper discusses how to correlate subwoofer model, frequency
Thota, Jagadeesh, Choi, Seungchan, Park, Jong-Suh
Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis2025-01-005805/05/2025
To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.
Yang, Wenlong, Melo, Andre
Investigation and Application of Tire Model to Optimize Road Noise2025-01-011105/05/2025
Tires have a significant impact on vehicle road noise. The noise in 80~160Hz is easily felt when driving on rough roads and has a great relationship with the tire structural design. How to improve the problem through tire simulation has become an important issue. Therefore, this paper puts forward the concept of virtual tire tuning to optimize the noise. An appropriate tire model is crucial for road noise performance, and the CDtire (Comfort and Durability Tire) model was used in the article. After conducting experimental validation to get an accurate tire model, adjust the parameters and structure of the tire model to generate alternative model scenarios. The transfer function of the tire center was analyzed and set as the evaluation condition for tire NVH (Noise, vibration, and harshness) performance. This enabled a comparison among various model scenarios to identify the best-performing tire scenario in focused frequency whose transfer function needed to be lowest. Manufacture the
Zhang, Ben, Yu Sr, Jing, Chen, Qimiao, Liu, Xianchen, Gu, Perry
Study of Sound and Cabin Touchpoint Contributions to Subjective Perception of Secondary Ride2025-01-006005/05/2025
Subjective perception of vehicle secondary ride is dependent on simultaneous touchpoint vibrations and audible inputs to the occupants. Standards such as ISO 2361 provide guidelines for objective assessments of human body thresholds to vibration [1]. However, when a human experiences vibration inputs at multiple touchpoints, as well as aural inputs, it becomes complicated to judge each individual contribution to the overall subjective perception [2]. Additional factors, such as ambient conditions, ergonomics, age, gender etc. also play a role. Secondary ride, which is defined as energy in the 10-30 Hz frequency range, is one such event that affects the customers’ perception of ride comfort and quality. The goal of this work is to develop a sound and vibration simulator model and execute a secondary ride jury study of vehicle driving over cleats. The aim of the study is to rank the contributions of each touch point vibration input, as well as sound to the overall subjective perception
Jayakumar, Vignesh, Joodi, Benjamin, Geissler, Christian, Pilz, Fernando, Lynch, Luke, Conklin, Chris, Weilnau, Kelby, Hodgkins, Jeffrey
Virtual Gear Noise Analysis and Case Design Investigation for Concept Parallel Axis Drive Unit2025-01-010205/05/2025
For electric vehicles, it is critical to develop drive units that produce a minimal amount of noise while meeting efficiency needs for a given application. Modern computational resources and accumulated experience allow for engineers to evaluate gear noise early in the development process and influence the design of the drive unit. This paper documents a high-fidelity virtual engineering approach to evaluate gear noise in a concept parallel axis drive unit and provide learnings to influence the design of external structures to improve NVH performance. By using the latest simulation tools to calculate and visualize the noise and vibration characteristics of the drive unit, designers and developers can implement design changes in optimization iterations to reduce noise and vibration. Gear harmonic response is firstly analyzed through a system model which considers structural deflection and misalignment, then a FE housing model is incorporated which is used for noise radiation evaluation
Lima, Luiz, Shi, Zhenghong, Xu, Hai, Reynolds, Craig, Miller, John
Mode Shape Identification Using Graph Neural Networks for Vehicle Structure Design2025-01-013105/05/2025
This paper introduces a novel, automated approach for identifying and classifying full vehicle mode shapes using Graph Neural Networks (GNNs), a deep learning model for graph-structured data. Mode shape identification and naming refers to classifying deformation patterns in structures vibrating at natural frequencies with systematic naming based on the movement or deformation type. Many times, these mode shapes are named based on the type of movement or deformation involved. The systematic naming of mode shapes and their frequencies is essential for understanding structural dynamics and “Modal Alignment” or “Modal Separation” charts used in Noise, Vibration and Harshness (NVH) analysis. Current methods are manual, time-consuming, and rely on expert judgment. The integration of GNNs into mode shape classification represents a significant advancement in vehicle modal identification and structure design. Results demonstrate that GNNs offer superior accuracy and efficiency compared to
Tohmuang, Sitthichart, Swayze, James L., Fard, Mohammad, Fayek, Haytham, Marzocca, Piergiovanni, Bhide, Sanjay, Huber, John
Localisation of Ultra-Short Sound Emissions from Automotive Components by Using the Sound Field Scanning Method2025-01-009205/05/2025
Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from
Rittenschober, Thomas
A Theoretical and Experimental Investigation of NVH of In-Wheel Reducer and Motor Drive System2025-01-000605/05/2025
To enhance the power density of the system and reduce production costs, the high-speed electric drive system featuring integrated design and control is poised to be the future development trend. However, the high speeds of motors and gear reducers can lead to challenges such as system reliability and issues related to NVH. This paper specifically addresses the NVH concerns associated with the in-wheel reducer and motor drive system (IWRMDS). First, a bench test scheme is established, and vibration and noise tests are conducted under a range of conventional operating conditions. The results indicate that at a torque of 200 Nm and a speed of 5500 rpm, the noise sound pressure level reaches 86.2 dB, highlighting significant vibration and noise issues within the system. Subsequently, Operational Deflection Shape (ODS) testing and analysis are performed on the system. It was discovered that the IWRMDS exhibits a relatively rich modal frequency spectrum, with the breathing mode being the
Huang, Chao, Xiong, Lu, Meng, Dejian, Gong, Yu, Guo, Han, Zhang, Mengyuan
A Comparative Analysis of Fault Diagnosis by Vibration Signals for Critical Gear Components in Electric Vehicle Motor Testing Machines Using Machine Learning Algorithms2025-01-004005/05/2025
Electric vehicles (EVs) are shaping the future of mobility, with drive motors serving as a cornerstone of their efficiency and performance. Motor testing machines are essential for verifying the functionality of EV motors; however, flaws in testing equipment, such as gear-related issues, frequently cause operational challenges. This study focuses on improving motor testing processes by leveraging machine learning and vibration signal analysis for early detection of gear faults. Through statistical feature extraction and the application of classifiers like Wide Naive Bayes and Coarse Tree, the collected vibration signals were categorized as normal or faulty under both loaded (0.275 kW) and no-load conditions. A performance comparison demonstrated the superior accuracy of the wide neural networks algorithm, achieving 95.3%. This methodology provides an intelligent, preventive maintenance solution, significantly enhancing the reliability of motor testing benches.
S, Ravikumar, Sharik, N, Syed, Shaul, V, Muralidharan, D, Pradeep Kumar
Electromagnetic and NVH Analysis of PMSM with Eccentricity and Rotor Magnetization Variations2025-01-004705/05/2025
Permanent magnet synchronous motors (PMSM) are among the most promising motors in electric vehicles due to their high torque density and efficiency. This paper is devoted to detailed electromagnetic investigations of permanent magnet synchronous motor, accounting for specific rotor eccentricity and uneven magnetization. A series of simulations are performed for a 90 HP interior PMSM to investigate the changes in the radial and tangential forces when the rotor is perfectly aligned or with static, dynamic, and mixed eccentricities. Besides, the influence of uneven magnetization due to manufacturing, demagnetization, and magnet deterioration is discussed. The forces are then used to load a vibro-acoustic model to evaluate the impact on the noise, vibration, and harshness (NVH) performance and predict the radiated sound power level for the different conditions.
Hadjit, Rabah, Kebir, Ahmed, Felice, Mario
A Review on Electric Vehicle NVH Challenges and Recent Trends2025-01-004205/05/2025
Electric vehicles (EVs) present a distinct set of challenges in noise, vibration, and harshness (NVH) compared to traditional internal combustion engine (ICE) vehicles. As EVs operate with significantly reduced engine noise, other sources of noise, such as motor whine, power electronics, and road and wind noise, become more noticeable. This review paper explores the key NVH issues faced by EVs, including high-frequency tonal noise from electric motors, gear meshing, and vibrations. Additionally, it examines recent advancements and trends in NVH mitigation techniques, such as active noise control, improved material insulation, and advanced vibration isolation systems. Furthermore, this paper discusses the role of computational tools, simulation technologies, and testing methodologies in predicting and addressing NVH concerns in EVs. By providing an in-depth analysis of the challenges and the latest innovations, this review aims to contribute to the ongoing development of quieter and
Hazra, Sandip, Khan, Arkadip Amitava
Metamaterial Application to Automotive Glass for Vibration Reduction and Reduced Noise Transmission2025-01-011905/05/2025
A proprietary metamaterial has been shown to reduce panel vibration. In this particular case, the metamaterial is designed to be attached to the edge of a glass panel and can reduce panel vibration and noise transmission due to wind or other sources into the vehicle interior. Acoustic transmission loss and panel vibration assessments show the benefit of this approach.
Sorenson, Steve, Li, Xiaopeng, Moore, Jaime, Robison, Scott
Vibration Refinement of Two Wheeler Sub Chassis and Aesthetic Parts Due to Engine Unbalanced Excitation Forces2025-01-011305/05/2025
Two wheeler is important and essential transportation mode in many of the countries across the globe. Designing a motorcycle with better riding comfort and minimal vibration are thus a major challenge for engineers now a day. Engine and road excitations are two source of vibration acting on motor bike or scooter both. These vibrations are transmitted to the chassis, sub chassis, aesthetic parts and then to the rider and pillion. Unwanted vibrations will create discomfort to the rider/pillion and produce noise. Hence, these need to be minimized. This study is focus on diagnosis and control of output vibration response of sub chassis/aesthetic parts due to engine unbalanced excitation force. There are numerous parameter of motor bike/scooter that governs the vibration response of sub chassis/aesthetic parts. Engine unbalanced inertia force characteristics and their transmission to rider and pillion has been studied and reported here. Environmental benefit demands for a complete noise
Khare, Saharash
Application of Hybrid SEA in Vehicle NV Package Optimization2025-01-005005/05/2025
As India’s economy expands and road infrastructure improves, the number of car owners is expected to grow substantially in the coming years. This market potential has intensified competition among original equipment manufacturers (OEMs) to position their products with a focus on cost efficiency while delivering a premium user experience. Noise and Vibration (NV) performance is a critical differentiator in conveying a vehicle's premiumness, and as such, NV engineers must strategically balance the achievement of optimal acoustic performance with constraints on cost, mass, and development timelines. Traditionally, NV package optimization occurs at the prototype or advanced prototype stage, relying heavily on physical testing, which increases both cost and time to market. Furthermore, late-stage design changes amplify these challenges. To address these issues, this paper proposes the integration of Hybrid Statistical Energy Analysis (HSEA) into the early stages of vehicle development
Rai, Nitesh, Mehta, Makrand, Ravindran, Mugundaram
Evaluation of Automotive Closure Design for High Frequency Acoustic Performance2025-01-004905/05/2025
A good Noise, Vibration, and Harshness (NVH) environment in a vehicle plays an important role in attracting a large customer base in the automotive market. Hence, NVH has been given significant priority while considering automotive design. NVH performance is monitored using simulations early during the design phase and testing in later prototype stages in the automotive industry. Meeting NVH performance targets possesses a greater risk related to design modifications in addition to the cost and time associated with the development process. Hence, a more enhanced and matured design process involves Design Point Analysis (DPA), which is essentially a decision-making process in which analytical tools derived from basic sciences, mathematics, statistics, and engineering fundamentals are used to develop a product model that better fulfills the predefined requirement. This paper shows the systematic approach of conducting a Design Point Analysis-level NVH study to evaluate the acoustic
Ranade, Amod A., Shirode, Satish V., Miskin, Atul, Mahamuni, Ketan J., Shinde, Rahul, Chowdhury, Ashok, Ghan, Pravin
Application of Blocked Force Methodology to an Electrified Beam Axle from a Medium-Duty Truck in Vehicle and in a Dynamometer Test Cell2025-01-005405/05/2025
The recent addition of fully electric powertrains to propulsion system options has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and a reduction gearbox. Improved metrics are also driven by the stiff suspension connections and lack of significant isolation compared to electric drive units. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle with a leaf spring suspension. The axle was tested
Shaw, Matthew D, Grimmer, Michael J
Indirect Blocked Force Measurement of a Hydraulic Power Pack for Structural Vibration Transmission into an Airframe2025-01-005205/05/2025
Centralization of electrically driven hydraulic power packs into the body of aircraft has increased attention on the noise and vibration characteristics of the system. A hydraulic power pack consists of a pump coupled to an electrical motor, accumulator, reservoir, and associated filter manifolds. In previous studies, the characteristics of radiated acoustic noise and fluid borne noise were studied. In this paper, we focus on the structure-borne forces generated by the hydraulic pump characterized through blocked force measurements. The blocked force of the pump was determined experimentally using an indirect measurement method. The indirect method required operation with part under test fixed to an instrumented receiver structure. Measured operational accelerations on the receiver plate were used in conjunction with transfer function measurements to predict the blocked forces. Blocked forces were validated by comparing directly measured accelerations to predicted accelerations at
Smither, Matthew, Tuyls, Zachary, Patel, Pratik, Yan, Xin, Herrin, David
Innovative High-Performance Active Dampers for Effective Mitigation of Helicopter Main Rotor Vibrations2025-01-016305/02/2025
Helicopter vibrations, primarily generated by the main rotor-gearbox assembly, are a major source of concern due to their impact on structural integrity, cockpit instrument durability, and crew comfort. These vibrations are mainly transmitted through the gearbox’s rigid support struts to the fuselage, leading to increased cabin noise and potential damage to critical components. This paper presents a solution for vibration mitigation which involves replacing traditional gearbox support struts with low-weight, high-performance active dampers. Developed by Elettronica Aster S.p.A., these active dampers are designed as electro-hydraulic actuators embedded within a compliant structure. The parallel nested configuration of the system enables high power densities and effective vibration control, significantly reducing the transmission of harmful vibrations to the fuselage. The comprehensive model-based design process is detailed, describing the development and use of a high-fidelity physics
Bertolino, Antonio Carlo, Sorli, Massimo, Porro, Paolo Giovanni, Galli, Claudio
Damping and Vibration Characteristics of Carbon Fiber Sandwich Beams with Corrugated Cores05-19-01-000504/26/2025
Composite sandwich beams are widely favored for their high strength-to-weight ratio, so understanding their vibration characteristics is important for optimizing designs in critical industries. This study investigates, through experimental and statistical analyses, the impact of core geometry on the vibration characteristics of epoxy/carbon fiber composite sandwich beams featuring sinusoidal and trapezoidal cores. Modal tests were conducted to determine natural frequencies, damping ratios, and mode shapes. The height and angle of the cores were treated as key independent factors influencing the beams’ vibration characteristics. In both of the cores the damping ratio values increased about 25% and 35% with increasing the height and angle of the sinusoidal and trapezoidal cores, respectively. Additionally, response surface methodology (RSM) was used for statistical analysis of these input parameters’ effects on damping properties, and the optimal values of core’s geometries were
Alwan, Majeed A., Abbood, Ahmed Sh., Farhan, Arkan J., Azadi, Reza
Identification of Input Force and Contribution for Electric Power UnitUtilizing Virtual Point2024-32-001504/18/2025
In this study, vibration characteristics inside an electric power unit at gravity center where direct measurement is impossible were estimated by using virtual point transformation to consider guideline for effective countermeasures to the structure or generated force characteristics inside the power source. Vibration acceleration, transfer function and the generated force in operation at the gravity center of the electrical power source were obtained by vibration characteristics at around the power source which can be measured directly. In addition, the transfer functions from the gravity center to the power source attachment points on the product were also estimated. And then, the contribution from the gravity center to the power unit attachment point was obtained by multiplying generated force with the transfer function. As results, the obtained total contribution was almost same with the actual measured vibration at the attachment point. Furthermore, the rotational contribution
Kubo, Ryoma, Hara, Kenta, Yoshida, Junji
Dependency of Gear Honing Machine Processing Accuracy on Machine Vibration and the Vibration Reduction Considering Contribution2024-32-002004/18/2025
In recent years, accurate gear processing is required for various products to improve efficient power transmission and small noise and vibration. On the other hand, the accuracy tends to be worse by high speed processing for increasing production efficiency. Therefore, we investigated relationship between gear honing machine vibration and the accuracy. The vibration acceleration of the honing machine was measured at various conditions, and the gear accuracy was measured after processing. As results, the accuracy was observed to be affected by both the original gear accuracy before honing processing and the gear secondary rotational vibration of the machine in operation. Subsequently, we applied transfer path analysis (TPA) to investigate which directional force in operation increased the vibration. As the results, the contribution from the input force at gear processing point along normal direction was the main contributor. Then, vibration transmission characteristics of the machine
Hanioka, Hiroaki, Ogawa, Yunosuke, Yoshida, Junji, Onishi, Yoichi, Kurokawa, Yasuhiro
Development of a Robust Framework for Fault Detection and Quantification in Automotive Drum Brakes Using Vibration Measurements and ANN10-09-03-002404/15/2025
Passenger safety is of utmost importance in the automotive industry. Hence, the health of the components, especially the brake system, should be effectively monitored. On account of the significance of artificial intelligence in recent times, any brake fault resulting during operation can be accurately detected using a combination of advanced measurement techniques and machine learning algorithms. The current study focuses on developing and evaluating a robust framework to quantify and classify the faults of a general automotive drum brake. For this purpose, a new experiment for a drum brake, which can be operated under a controlled environment with known levels of faults, is developed. The experiment is instrumented to measure the fundamental dynamic signals (such as brake torque, the angular velocity of the brake drum, and brake shoe accelerations) during a braking event. The response signals from several experiments with various faults and operating conditions serve as the input
Yella, Akash, Bharinikala, Yuva Venkat Ajay, Sundar, Sriram
A Comparative Study of Optimization Algorithms for 6DOF Design in Electric Vehicle Powertrain Mounting Systems2025-01-865004/01/2025
Optimizing engine mounting systems is a complex task that requires balancing the isolation of vehicle vibrations with controlling powertrain movement within a limited dynamic envelope. Six Degrees of Freedom (6DOF) optimization is widely used for mounting stiffness and location optimization. This study investigates the application of various optimization algorithms for 6DOF analysis in engine mount design, where the system’s stochastic behaviour and probabilistic characteristics present additional challenges. Selecting an appropriate optimization framework is essential for achieving accurate and efficient NVH results. Recent advancements in research have introduced several 6DOF optimization algorithms to determine the optimal stiffness and location of engine mounts. The study evaluates a range of optimization methods, including Simultaneous Hybrid Exploration that is Robust, Progressive and Adaptive (SHERPA), Quadratic Programming (QP), Genetic Algorithm (GA), Particle Swarm
Hazra, Sandip, Khan, Arkadip
Impact of Preload and Amplitude on the High-Frequency Behaviour of Rubber Bushings in Electric Vehicles: An Experimental Study2025-01-825404/01/2025
Electric vehicles (EVs) are particularly susceptible to high-frequency noise, with rubber eigenmodes significantly influencing these noise characteristics. Unlike internal combustion engine (ICE) vehicles, EVs experience pronounced variations in dynamic preload during torque rise, which are substantially higher. This dynamic preload variation can markedly impact the high-frequency behaviour of preloaded rubber bushings in their installed state. This study investigates the effects of preload and amplitude on the high-frequency dynamic performance of rubber bushings specifically designed for EV applications. These bushings are crucial for vibration isolation and noise reduction, with their role in noise, vibration, and harshness (NVH) management being more critical in EVs due to the absence of traditional engine noise. The experimental investigation examines how preload and excitation amplitude variations influence the dynamic stiffness, damping properties, and overall performance of
Hazra, Sandip, Khan, Arkadip Amitava
Research on Shuffle Reduction Control in Dual Motor Hybrid System Based on the Motor Torque Intervention2025-01-851704/01/2025
Due to the frequent and significant changes of the motor torque of hybrid vehicles during driving often occurring with the driving conditions, and the existence of the transmission tooth surface switching caused by the change in torque direction, as well as the underdamping characteristics caused by the relatively simple transmission system, the vehicle is prone to vehicle body shaking problems under conditions such as the transformation from acceleration conditions to energy recovery conditions, and exit from energy recovery. In order to ensure the ride smoothness of the hybrid vehicle while improving its power response performance, aiming at the underdamping characteristics of its transmission system, this paper develops a transmission PCM vibration suppression control strategy based on the vehicle control system to enhance the torque response and smoothness after Tip out or Tip in after braking. This strategy includes the identification of preconditions and the active intervention
Jing, Junchao, Zhang, Junzhi, Zuo, Botao, Liu, Yiqiang, Huang, Weishan, Xue, Tianjian
Vehicle Interior Audio System Noise Prediction Based on Inverse Acoustic Approach and Directivity Pattern2025-01-864004/01/2025
Automotive audio components must meet high quality expectations with ever-decreasing development costs. Predictive methods for the performance of sound systems in view of the optimal locations of loudspeakers in a car can help to overcome this challenge. Use of simulation methods would enable this process to be brought up front and get integrated in the vehicle design process. The main objective of this work is to develop a virtual auralization model of a vehicle interior with audio system. The application of inverse numerical acoustics [INA] to source detection in a speaker is discussed. The method is based on truncated singular value decomposition and acoustic transfer vectors The arrays of transfer functions between the acoustic pressure and surface normal velocity at response sites are known as acoustic transfer vectors. In addition to traditional nearfield pressure measurements, the approach can also include velocity data on the boundary surface to improve the confidence of the
Baladhandapani, Dhanasekar, Thaduturu, Sai Ravikiran, Du, Isaac
Robust Design of Automotive Inverter Components using Tests and Simulations2025-01-863904/01/2025
Vibration qualification tests are indispensable for vehicle manufacturers and suppliers. Carmakers’ specifications are therefore conceived to challenge the mechanical endurance of car components in the face of numerous in-service detrimental phenomena: In automotive industries, components are commonly qualified by means of a test without failure, the goal being to determine whether it will or not "pass" customer requirements. Validation of newly designed components is obtained via bench test and structural simulation. Simulation has gained traction in recent years because it represents the first step of the design validation process. In particular, FEA simulations are powerful to predict the dynamic behavior of physical testing on prototypes, enable engineers to optimize the design and predict the durability. This paper illustrates how FEA simulations were applied to product validation in the pre-serial phase to optimize manufacturing process. In particular, we will focus on the PCB of
Duraipandi, Arumuga Pandian, Leon, Renan, Bonato, Marco, Raja, Antony Vinoth, Kumar, Lalith, Niwa, Takehiro
Rough Road Vehicle Dynamics Analysis for Vehicle Vibration Assessment2025-01-830604/01/2025
This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model including non-linear tuning elements and flexible vehicle body is simulated on ride roads. The goal of the simulation is acceleration responses at the passenger locations in frequency domain. Body interface loads are recovered from the vehicle dynamic simulations. Frequency response function (FRF) of the body structure is ready in a fashion that input forces are applied to all body interface locations to the suspension and powertrains. This will give acceleration response sensitivity of the body structure to each body interface. The sum of body interface loads multiplied by FRF at each interface produces acceleration responses in frequency domain. A mid-size sedan model was used to demonstrate the process. A full vehicle dynamics model using Ansys Motion was simulated on a virtual ride road at a constant speed. The body loads were recovered in time domain
Hong, Hyung-Joo, Maddula, Pavan Kumar, Jun, Hyochan
Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System2025-01-826804/01/2025
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring
Hao, Qi, Zhu, Yuntao, Sun, Wen, Sun, Kai, Sun, Zhiyong, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin
Research on Motor Harmonic Injection Control in Hybrid System to Suppress the Torsional Vibration2025-01-851504/01/2025
Based on the harmonic current injection method used to suppress the torsional vibration of the electric drive system, the selection of the phase and amplitude of the harmonic current based on vibration and noise has been explored in this paper. Through the adoption of the active harmonic current injection method, additional torque fluctuations are generated by actively injecting harmonic currents of specific amplitudes and phases, and closed-loop control is carried out to counteract the torque fluctuations of the motor body. The selection of the magnitude of the injected harmonic current is crucial and plays a vital role in the reduction of torque ripple. Incorrect harmonic currents may not achieve the optimal torque ripple suppression effect or even increase the motor torque ripple. Since the actively injected harmonic current is used to counteract the torque ripple caused by the magnetic flux linkage harmonics of the motor body, the target harmonic current command is very important
Jing, Junchao, Zhang, Junzhi, Liu, Yiqiang, Huang, Weishan, Dai, Zhengxing
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