scholarly journals Vibration Transfer Path Analysis and Path Ranking for NVH Optimization of a Vehicle Interior

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
B. Sakhaei ◽  
M. Durali
Keyword(s):  
Quality Assurance ◽  
Path Analysis ◽  
Critical Issue ◽  
Vehicle Interior ◽  
Noise And Vibration ◽  
Good Compliance ◽  
Transfer Path ◽  
Good Ability ◽  
Engine Mount ◽  
Transfer Path Analysis

By new advancements in vehicle manufacturing, evaluation of vehicle quality assurance has got a more critical issue. Today noise and vibration generated inside and outside the vehicles are more important factors for customers than before. So far several researchers have focused on interior noise transfer path analysis and the results have been published in related papers but each method has its own limitations. In present work, the vibration transfer path analysis and vibration path ranking of a car interior have been performed. As interior vibration is a source of structural borne noise problem, thus, the results of this research can be used to present the structural borne noise state in a vehicle. The proposed method in this paper does not need to disassemble the powertrain from the chassis. The procedure shows a good ability of vibration path ranking in a vehicle and is an effective tool to diagnose the vibration problem inside the vehicle. The simulated vibration spectrums in different speeds of the engine have a good compliance with the tested results; however, some incompatibilities exist and have been discussed in detail. The simulated results show the strength of the method in engine mount optimization.

Transfer Path Analysis of a Vehicle Subframe: Measurements in Six Degrees of Freedom

1997 ◽  
Author(s):  
Lars Ivarsson
Keyword(s):  
Path Analysis ◽  
Transfer Functions ◽  
The Body ◽  
Impedance Method ◽  
Transfer Path ◽  
Rotational Components ◽  
Improve Measurement ◽  
Engine Mount ◽  
Six Dof ◽  
Transfer Path Analysis

Abstract A Transfer path analysis (TPA) is undertaken for a car subframe concerning six DOF of freedom and two coupling points up to 500 Hz. Integrated stingers have been developed to improve measurement results. The relative importance of the rotational components is investigated. The blocked impedance method has been used to couple the subframe to the car body using measured mobilities via two isolators out of four. The sound sensitivity is measured directly for the coupled system and compared with the total sum of the calculated transfer path components which are calculated with measured mobilities and transfer functions. Calculated and measured results show good agreement. The importance of the rotational paths depends on the characteristics of the isolator and the structures where it is mounted. It was found that the front mount position is more sensitive to rotations compared to the rear mount position. The rear mount position is also a much stiffer construction. It was found that above 220 Hz, the rotational paths are of the same importance as the translational paths when both points were connected to the body frame. It was also found that for the rear mount position, only one translational transfer path dominates. These conclusions do not differ especially for different excitation directions at the engine mount position.

Idle shake vibration optimization of an engine mounting system through the practical application of transfer path analysis

2020 ◽  
Vol 68 (6) ◽  
pp. 459-469
Author(s):  
E. Courteille ◽  
F. Mortier
Keyword(s):  
Path Analysis ◽  
Hybrid Approach ◽  
Measurement Data ◽  
Vibration Level ◽  
Practical Application ◽  
Idle Speed ◽  
Transfer Path ◽  
Engine Mount ◽  
Transfer Path Analysis ◽  
Idle Shake

This article presents a practical application of experimental transfer path analysis (TPA) for optimizing idle shake vibrations of a front-wheel-drive car with a transversely mounted four-cylinder diesel engine. Performance control of the vehicle engine mounting system must take into account the multiple dynamic interactions between the engine mounting system, subframe modes and the vehicle suspension. Experimental methods can be used in conjunction with simulations to design and optimize the engine mounting system. TPA is a powerful tool for the diagnosis of vibration and noise transmission via multiple solid paths. TPA allows a quick diagnosis of the engine mounting system performances on vehicle comfort. A strong synergy between numerical model and experimental data finally makes it possible to find better design alternatives, not necessarily obvious to the designer. This study is the guideline for an optimization of the engine mount noise vibration and harshness (NVH) performances by using a hybrid approach, combining an analytical approach and measurement data. First, a diagnosis of the transmission of structure-borne vibrations via the engine mounting system to the seat floor is done at constant idle speed. This method is used to rank individual engine mount contributions in the low-frequency vibration level inside the vehicle. Then, an original approach allows the optimization of the vibration level at idle speed by offsetting contributions of the engine mount paths by adding damping in the right engine mount. This approach has led to the design and validation of an original double inertia-track hydroelastic mount prototype which allows a 5-dB reduction on the seat floor vibration level. The future development of a new version is planned to confirm and optimized the obtained results. The length of the second inertia track will be increased to reach the targeted characteristics, and the adjustment system will be removed to respect the overall dimension constraints of the mount.

Case study: Separating source contributions of vehicle interior noise by operational transfer path analysis

2021 ◽  
Vol 69 (1) ◽  
pp. 39-52
Author(s):  
Ming-Hung Lu ◽  
Ming Une Jen ◽  
Dennis de Klerk
Keyword(s):  
Path Analysis ◽  
Interior Noise ◽  
Vehicle Interior ◽  
Noise Sources ◽  
Tire Noise ◽  
Transfer Path ◽  
Vehicle Interior Noise ◽  
Transfer Path Analysis ◽  
Noise Contribution

The perception of vehicle interior noise is a key quality index to customers and automakers alike. By tracing noise back to key noise sources and paths, one can focus their refinement efforts. Aiming at the most efficient way to identify the primary noise sources in a vehicle cabin, this article establishes a framework of operational transfer path analysis (OTPA) for separating contributions of noise sources by operational measurements only. OTPA model design, measuring essentials and synthesis method used for separating vehicle interior noise contributions from the powertrain, tires andwindwere described in detail. To comprehend the implementation of OTPA on noise source separation, this article also addresses an exemplification study on an electric vehicle. In the case study illustrated, both spectral map and order extractions were used to validate if the OTPA synthesized results of the powertrain noise contribution agreed with the measured results. Tire noise contribution was validated using the tires driven by the dynamometer along with all other systems switched off. With well-validated OTPA model for the powertrain and tires, further individual path breakdown of the powertrain and tire noise then was investigated to identify key contributors to the interior noise. After clearly separating interior noise contributions, one therefore could design effective countermeasures to mitigate the dominant noise sources. With appropriate scheme of measurement and synthesis, the OTPA technique could therefore effectively serve target setting and refinement focus at foremost noise contributors.

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