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 Contribution

2024-32-0020

04/18/2025

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 ANN

10-09-03-0024

04/15/2025

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

Robust Design of Automotive Inverter Components using Tests and Simulations

2025-01-8639

04/01/2025

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

Research on Shuffle Reduction Control in Dual Motor Hybrid System Based on the Motor Torque Intervention

2025-01-8517

04/01/2025

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

Rough Road Vehicle Dynamics Analysis for Vehicle Vibration Assessment

2025-01-8306

04/01/2025

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 System

2025-01-8268

04/01/2025

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

Analysis and Validation of Torque Ripple Cancellation to Reduce Electric Motor Noise for Electric Vehicles

2025-01-8573

04/01/2025

The electric motor is a significant source of noise in electric vehicles (EVs). Traditional hardware-based NVH optimization techniques can prove insufficient, often resulting in trade-offs between motor torque or efficiency performance. The implementation of motor control-based torque ripple cancellation (TRC) technology provides an effective and flexible solution to reduce the targeted orders. This paper presents an explanation of the mathematical theory underlying the TRC method, with a particular focus on the various current injection methods, including those that allow up to 4DOFs (degrees-of-freedom). In the case study, the injection of controlled fifth or seventh order current harmonics into a three-phase AC motor is shown to be an effective method for cancelling the most dominant sixth order torque ripple. A dedicated feedforward harmonic current generation module is developed the allows the application of harmonic current commands to a motor control system with adjustable

He, Song, Gong, Cheng, Chang, Le, Peddi, Vinod, Zhang, Peng, GSJ, Gautam

Impact of Preload and Amplitude on the High-Frequency Behaviour of Rubber Bushings in Electric Vehicles: An Experimental Study

2025-01-8254

04/01/2025

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 Motor Harmonic Injection Control in Hybrid System to Suppress the Torsional Vibration

2025-01-8515

04/01/2025

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

Vehicle Interior Audio System Noise Prediction Based on Inverse Acoustic Approach and Directivity Pattern

2025-01-8640

04/01/2025

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

A Comparative Study of Optimization Algorithms for 6DOF Design in Electric Vehicle Powertrain Mounting Systems

2025-01-8650

04/01/2025

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

Multidimensional Coupling Effects and Vibration Suppression for In-Wheel Motor–Driven Electric Vehicle Suspension Systems: A Review

10-09-02-0013

03/26/2025

In this article, a comprehensive review regarding the vibration suppression for electric vehicles with in-wheel motors is provided. Most of the current reviews on the suspension performance of the in-wheel motor electric vehicles have seldom discussed the issue of the multidimensional coupling between the vertical and longitudinal dynamics of the vehicle. This article not only addresses this shortcoming, but also provides an all-inclusive review of these effects while considering the electrical–mechanical coupling on the vehicle dynamics. This article uses a state-of-the-art search strategy to search and process relevant and high-quality studies in the area. First, various negative effects of the deployment of the in-wheel motor, such as the increased unsprung mass, multidimensional electromagnetic–mechanical coupling, and the coupled vehicle vertical–longitudinal dynamics, are discussed. A review of the studies related to the unbalanced electromagnetic force and its coupling with the

Marral, Usman Iqbal, Du, Haiping, Naghdy, Fazel

A reduced-order beam modelling approach of BIW for torsional and bending stiffness optimization

2025-28-0187

02/07/2025

Noise, Vibration, and Harshness (NVH) simulations of vehicle bodies are crucial for assessing performance during the design phase. However, these simulations typically require detailed computer-aided design (CAD) models and are time-consuming. In the early stages of vehicle development, when only high-level vehicle sections are available, designing the body-in-white (BIW) structure to meet target values for bending and torsional stiffness is challenging and often requires multiple iterations. To address these challenges, this study deploys a reduced-order beam modelling approach. This method involves identifying the beam-like sections and major joints within the BIW and calculating their sectional properties (area, area moments of inertia along the plane’s independent axes, and torsion constant). These components form a simplified skeleton model of the BIW. Load and boundary conditions are applied to the suspension mount locations at the front and rear of the vehicle, and torsional and

Khan, Mohd Zishan Ali, Thanapati, Alok, Deshmukh, Chandrakant

Vibration Suppression of a Flexible Appendage and Pitch Angle Fuzzy Regulation of a Spacecraft

01-18-01-0004

02/05/2025

In this work, the large-angle rotational movement and vibration suppression of a flexible spacecraft are carried out based on an adjustable system. First the spacecraft model is transformed into a canonical affine control form, then two fuzzy systems are used: The first (of Takagi–Sugeno type) estimates the feedback linearization control law as a whole, while the second (of Mamdani type) adjusts and stabilizes the control parameters using the gradient descent technique and based on the minimization of the control error rather than the tracking error. Stability results are presented in terms of Lyapunov’s theory, and simulation tests illustrate the significant transient robustness of the closed-loop system against perturbations, the accurate trajectory control, and vibration suppression of the flexible spacecraft. Consequently, as will be shown later, the error will stay confined and converges quickly to zero, confirming the smoothing property of the proposed method using fuzzy logic

Bahita, Mohamed

Formulation of Power Spectral Density of Fuel Cell Stacks in Different Vehicle Models Based on Road Driving Conditions

2025-01-7083

01/31/2025

The durability of fuel cell vehicle (FCV) has always been one of the key factors affecting its large-scale application. However, the durability test methods of FCV and its key components, fuel cell stack (FCS), are incomplete all over the world, especially the lack of vibration test method on FCV. Focused on the FCS, this paper collects the road load spectrum of different vehicle models in their typical working conditions, so as to obtain the power spectral density of FCS of different vehicle models, which is used as the input signal of durability test. Through the FCS testing and analysis of fuel cell passenger car, bus, tractor and cargo van, the results show that the vibration intensity in three directions of FCS of different models is basically less than that of power battery, and only the FCS of fuel cell bus is greater than that of power battery in the direction of vehicle travel.

Wang, Guozhuo, Wu, Zhen, Guo, Ting, Wu, Shiyu, Liang, Rongliang, Nie, Zhenyu

Experimental Study on Vibration Aging Performance of Vehicle Carbon Canisters

2025-01-7030

01/31/2025

Due to the vibration of the vehicle, the performance of the vehicle carbon canisters will be changed, which will affect its control effect on the fuel evaporation emission. In this study, a vibration test platform capable of simulating vehicle vibration characteristics was used to simulate the possible vibration effects of the vehicle carbon canisters, and to analyze the absorption and desorption performance of the carbon canisters before and after long-term operation and its influence on vehicle evaporation emissions. The results show that the carbon canisters will precipitate the carbon powder after the continuous action of the forward and backward vibration of the vehicle. As a result, the ultimate adsorption and desorption amount of fuel vapor decreased, and the adsorption amount decreased more obviously. In the 48-hour Diurnal Breathing Loss (DBL) test, fuel vapor diffusion is more difficult due to the increased flow resistance of the carbon canisters after vibration, and fuel

Yu, Xiaohong, Liu, Yiyao, Feng, Yifang, Zheng, Yushuo, Chen, Tao, Zhao, Hua

Research of Pressure Control Based on Dither

2025-01-7040

01/31/2025

The purpose of the paper is to study the impact of dither on how to improve the pressure control capability in common rail system. The dither is directly operating to the inlet metering valve and making the metering flow accuracy. The correlation between rail pressure and metering flow was analyzed. Optimizing the inlet metering valve control is to improve the pressure control. To overcome the hysteresis problem of the inlet metering valve and improve its stability and rapidity on the pressure control. The PID control strategy based on the pressure control were applied in the common rail system and many papers have introduced the logical. But the dither application was seldom introduced in the common rail system. The dither was specified for the inlet metering valve. With the proper dither signal, the stick-slip motion of the metering valve spool converted to a steady one and the dynamic performance was optimized. To verify the theoretical and calibrated the proper dither signal, the

Kuang, Pengda, Chen, Huiqing, Zhang, Jing, Ran, Ye

Pressure-Dependent Nonlinearities of a Compact Hydropneumatic Strut with Integrated Gas–Oil Chamber

10-09-01-0008

01/24/2025

Hydropneumatic Struts (HPS) are widely implemented in automobile, aerospace, and construction industries, mainly for the purpose of vibration and shock absorption. The HPS design with integrated gas–oil chamber is relatively more compact and robust, while mixing gas and oil inside the HPS generates gas–oil emulsion and more nonlinearities. This study formulated a nonlinear analytical model of the compact HPS with gas–oil emulsion, considering the real gas law and pressure-dependent LuGre friction model. The polytropic version of the van der Waals (vdW) method for real gas is applied to represent the thermodynamic behavior of nitrogen. The experimental data were collected at a near temperature of 30°C with three charging pressures under excitations in the frequency range of 0.5–6 Hz, considering two flow connection configurations between chambers as one- and two-bleed orifice. The nonlinear behavior of the gas volume fraction of the emulsion was identified based on peak strut velocity

Seifi, Abolfazl, Yao, Yumeng, Yin, Yuming, Moore, Masih, Rakheja, Subhash

Fault Detection of Diesel Engines Using Artificial Neural Network

03-18-02-0010

01/20/2025

This study presents a method for identifying the reliability state of diesel engines by utilizing artificial neural networks (ANNs). The Sulzer 6AL20/24 marine diesel engine was selected as the test subject for this research. Vibration signals were collected during tests conducted on a laboratory test stand under normal operating conditions and during simulations of six different engine faults. Next, the recorded signals were analyzed and transformed into labeled samples for supervised learning. In this phase, the time histories of the vibration signals were divided into segments and augmented, with several key features calculated for each segment. Highly correlated signals were excluded from further analysis based on the Pearson correlation coefficient. The processed samples were then used to train and fine-tune the ANN. The trained ANN was subsequently used to identify the engine’s reliability state and classify the present fault type. To evaluate the effectiveness of the proposed

Pająk, Michał, Kluczyk, Marcin, Muślewski, Łukasz, Lisjak, Dragutin

Model Based Emissions and NVH Optimization

2024-36-0059

12/20/2024

Throughout the years, the legislations which drive the vehicle development have experimented constant evolutions. Especially when it comes about pollutant emissions and NVH ( Noise, Vibration & Harshness). However, it is complex to understand which calibration strategy promotes the best balance about lowest levels of emissions, vibrations, and noise if considered the number of inputs to be explored, becoming the searching for the optimum calibration a huge challenge for the development engineering team. This work proposes a methodology development in which complex problems can be solved by model based solutions regarding the best balance finding of emissions reduction and noise attenuation. The methodology is based in machine learning approach which provides a virtual behavior of engine phenomena making possible a wider comprehension of the problem and hence the opportunity to explore enhanced solutions. The study case scenario used to apply the method was a 6.4 liters engine which

Ruiz, Rodrigo Peralta Moraes, Santos, Lucas Resende, Nascif, Gabriel Nobre Alves, Oliveira Ribeiro, Douglas, Pereira, Willyan

An Experimental Study of White Deposit Formation on IG Coil in SI Engine

2024-28-0206

12/05/2024

This study meticulously examines the ignition coil (IG), a pivotal component in engine operation, which transforms the low voltage from the battery into the high voltage necessary for spark plug electrode flashover, initiating the combustion cycle. Considering the importance of IG coils in engine operation which has a direct impact on the engine performance. Any failure in the IG coils is judged as a critical failure and encompasses severe repercussions. The paper details an investigation into the issue of ‘White Deposition’ on IG coils. White deposit was observed in IG Coils during new model development in bench level durability test. A comprehensive failure analysis was conducted, employing vibration analysis, thermal analysis, and chemical analysis of the white deposits to ascertain the root cause. Subsequent to identifying the root cause, the study elaborated on hardware design enhancements as a solution. These design changes were rigorously tested on engine benches, confirmed for

Patel, Hardik Manubhai, Gupta, Vineet, Chand, Subhash, Kumar, Nitish

A Study on Powertrain Modes for Optimizing the NVH Performance

2024-28-0187

12/05/2024

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

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

Smart Contact Lens for Glaucoma Detection

TBMG-52160

12/01/2024

Researchers have been testing ways to continuously and more comfortably detect these tiny fluctuations in pressure. A prototype smart contact lens measures eye pressure accurately, regardless of temperature. The contact lens wirelessly transmits real-time signals about eye pressure across a wide range of temperatures.

Research on the Application of High-Static-Low-Dynamic Stiffness Vibration Isolator in Electro-Optical Pods of Unmanned Aerial Vehicles

2024-01-7015

11/15/2024

With the rapid advancement in unmanned aerial vehicle (UAV) technology, the demand for stable and high-precision electro-optical (EO) pods, such as cameras, lidar sensors, and infrared imaging systems, has significantly increased. However, the inherent vibrations generated by the UAV’s propulsion system and aerodynamic disturbances pose significant challenges to the stability and accuracy of these payloads. To address this issue, this paper presents a study on the application of high-static low-dynamic stiffness (HSLDS) vibration isolation devices in EO payloads mounted on UAVs. The HSLDS system is designed to effectively isolate low-frequency and high-amplitude vibrations while maintaining high static stiffness, ensuring both stability during hovering and precise pointing capabilities. A nonlinear dynamic system model with two degrees of freedom is formulated for an EO pod supported by HSLDS isolators at both ends. The model’s natural frequencies are determined, and approximate

Tian, Yishen, Guo, Gaofeng, Wang, Guangzhao, Wei, Wan, Bao, Lingcong, Dong, Guan, Li, Liujie

An Active Control Method Based on the Study of Dynamic Characteristics of Integrated Electric Drive Systems

02-18-01-0002

11/13/2024

Integrated electric drive systems are characterized by high power density, reliability, and controllability, making them increasingly prevalent in the realm of electric commercial vehicles. However, the direct coupling between the motor shaft and the transmission system has introduced a series of undesirable torsional vibration phenomena. To investigate the dynamic characteristics of electric drive systems in operation for electric commercial vehicles, a comprehensive modeling approach is employed. This modeling framework takes into account key factors such as gear backlash, structural flexibility, and electromagnetic spatiotemporal excitations. Based on this model, the influence of the electrical system on time-varying gear mesh stiffness, gear transmission error, bearing forces, and other factors is investigated. Building upon this foundation, the article proposes an approach for active harmonic voltage injection. This method effectively reduces torque fluctuations, decreases the

Xi, Xin, Chen, Xiaoli, Zhao, Hongyang, Zhao, Xuan, Wei, Jing, Liu, Yonggang

Development and Experimental Validation of a Physics-Based Identification and Mitigation Strategy for Torsional Vibratory Behavior in Medium-Duty Commercial Vehicle Drivelines

02-18-01-0001

11/08/2024

Torsional vibration generated during operation of commercial vehicles can negatively affect the life of driveline components, including the transmission, driveshafts, and rear axle. Undesirable vibrations typically stem from off-specification parts, or excitation at one or more system resonant frequencies. The solution for the former involves getting the system components within specification. As for the latter, the solution involves avoiding excitation at resonance, or modifying the parameters to move the system’s resonant frequencies outside the range of operation through component changes that modify one, or more, component inertia, stiffness, or damping characteristics. One goal of the effort described in this article is to propose, and experimentally demonstrate, a physics-based gear-shifting algorithm that prevents excitation of the system’s resonant frequency if it lies in the vehicle’s range of operation. To guide that effort, analysis was conducted with a numerical simulation

Dhamankar, Shveta, Ali, Junaid, Parshall, Evan, Shaver, Gregory, Evans, John, Bajaj, Anil K.

A Metamaterial that Traps, Amplifies Micro-Vibrations in Small Areas

TBMG-51946

11/01/2024

The Korea Research Institute of Standards and Science (KRISS) has developed a metamaterial that traps and amplifies micro-vibrations in small areas. This innovation is expected to increase the power output of energy harvesting, which converts wasted vibration energy into electricity, and accelerate its commercialization.

Investigation of Mid-Frequency Interior Noise due to Tyre-Road Interaction

2024-28-0005

10/17/2024

Over the past twenty years, the automotive sector has increasingly prioritized lightweight and eco-friendly products. Specifically, in the realm of tyres, achieving reduced weight and lower rolling resistance is crucial for improving fuel efficiency. However, these goals introduce significant challenges in managing Noise, Vibration, and Harshness (NVH), particularly regarding mid-frequency noise inside the vehicle. This study focuses on analyzing the interior noise of a passenger car within the 250 to 500 Hz frequency range. It examines how tyre tread stiffness and carcass stiffness affect this noise through structural borne noise test on a rough road drum and modal analysis, employing both experimental and computational approaches. Findings reveal that mid-frequency interior noise is significantly affected by factors such as the tension in the cap ply, the stiffness of the belt, and the properties of the tyre sidewall.

Subbian, Jaiganesh, M, Saravanan

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