Analysis and Study of the Transmission Path Based on the Body and NVH

2013 ◽  
Vol 385-386 ◽  
pp. 272-275
Author(s):  
Xia Liu ◽  
Hua Jin Yan ◽  
Xiu Jie Liu ◽  
Xia Sun
Keyword(s):  
Path Analysis ◽  
Modal Analysis ◽  
Theoretical Basis ◽  
Exhaust System ◽  
The Body ◽  
Structural Damping ◽  
The Road ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Noise Vibration

In the field of automotive engineering, noise and vibration in the car comes mainly from the engine and the road passed through the body, suspension, mount and exhaust system path to the car or reverberation. So this article , a model of white body transfer path analysis and research, improves the rigidity of white body, to reduce noise, vibration, and weight is reduced, and find out the resonance phenomena because of insufficient stiffness of car body, combining body CAE modal analysis results provide the theoretical basis for the optimization of structural damping.

scholarly journals Improved vehicle interior structure-borne noise induced by the powertrain using parallel dry friction damper

2017 ◽  
Vol 37 (2) ◽  
pp. 295-312 ◽  
Author(s):  
Eid Saber Mohamed ◽  
Shawki Abouel-Seoud ◽  
Manar Eltantawie ◽  
Abdelfattah Mohamded ◽  
Mohamed Salah
Keyword(s):  
Path Analysis ◽  
Dry Friction ◽  
Transfer Functions ◽  
The Body ◽  
Interior Noise ◽  
Interior Structure ◽  
Friction Damper ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Noise Vibration

Because of the higher requirements for vehicle comfort and people’s increasing ecological consciousness, research on the interior noise in a vehicle has received wide attention, among which structure-borne noise is hard to diagnose. To solve the problem, the transfer path analysis method of powertrain structure-borne noise has been systematically analyzed. By introduction of the powertrain source-path-receiver model, this method enables the researchers to estimate and study the noise, vibration, and harshness transfer functions and their operational forces. The aim is to further improve noise, vibration, and harshness with minimal negative impact on other vehicle attributes, such as ride comfort, handling, drivability, durability, etc. In this article, a parallel dry friction damper was added to the vehicle nearside powertrain mount, which is the most significant one to the receiver of passenger vehicle for improving its interior structure-borne noise induced by the engine. The test vehicle was a midsize executive vehicle. Since the structure-borne noise is composed of multiple paths, then the transfer path analysis test of the vehicle was carried out, and the transfer function and operational data at speed range started from 20 to 100 km/h were obtained. On the basis of the transfer path analysis results and the above principle, the friction damper on the body side of the nearside mount is improved by combination of the experimental transfer path analysis and the final measurements. The results indicate that a significant reduction for the A-weighted sound pressure level of the interior noise has been gained when the frictional damper was added to conventional mount.

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.

Transfer Path Analysis of Body Panel Participation Using a Structural-Acoustic Finite Element Model

2012 ◽  
Author(s):  
Shung H. Sung ◽  
Donald J. Nefske
Keyword(s):  
Finite Element ◽  
Path Analysis ◽  
Element Model ◽  
Operating Conditions ◽  
The Body ◽  
Interior Noise ◽  
Theoretical Development ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Body Panel

In transportation vehicles under operating conditions, interior noise frequently results from forces transmitted through the vehicle structure that excite body panel vibrations that couple with the body modes to radiate noise to the interior. The body panel participations to the interior noise that result from the force transfer paths can be identified using acoustic and structural-acoustic finite element models of the vehicle. This paper describes the transfer path analysis method to identify the body panel and modal participations for prescribed forcing excitations to the vehicle and to evaluate the effect of structural modifications. The theoretical development of the structural-acoustic finite element method and its example applications to two automotive vehicles are presented.

An experimental investigation of resonance sources and vibration transmission for a pure electric bus

2019 ◽  
Vol 234 (4) ◽  
pp. 950-962
Author(s):  
Mengyuan Zeng ◽  
Bohuan Tan ◽  
Fei Ding ◽  
Bangji Zhang ◽  
Hongtao Zhou ◽  
...  
Keyword(s):  
Path Analysis ◽  
Masking Effect ◽  
Coupling Vibration ◽  
Analytical Strategy ◽  
Vibration Transmission ◽  
Order Analysis ◽  
Transfer Path ◽  
Electric Bus ◽  
Transfer Path Analysis ◽  
Noise Vibration

Electric vehicles generally have a better noise, vibration, and harshness quality than traditional vehicles due to the relatively quiet electric motors. By contrast, the noise, vibration, and harshness issues of the driveline system become more outstanding and significant in the absence of the “masking effect” by the engine. The electrification of the powertrain has also brought many changes in the sources or transmission of vibration, which has led to some new noise, vibration, and harshness issues. Specifically, the intense vibration of the prototype bus appears when driving in third gear, which makes the passengers uncomfortable. This paper presents an efficient analytical strategy for identifying the resonance sources and vibration transmission for a pure electric bus. The strategy incorporates order analysis, operating deflection shape, and transfer path analysis. Order analysis shows that the resonance is primarily caused by the second-order excitation associated with the driveline, and the vibration sources are further identified using operating deflection shape analysis. Moreover, the vibration transfer paths from the driveline to the bus floor are quantitatively determined by the transfer path analysis method. The results show that the coupling vibration of the powertrain and the rear drive axle, which amplifies the resonance of the whole driveline, is transmitted to the bus floor primarily through powertrain mounts and V rods. Based on the results, the design and structure modifications of the driveline and transfer paths are recommended to handle this issue. The proposed identification strategy would be beneficial for accurate and efficient engineering troubleshooting on the vibration issues.

Vibration Transfer Path Analysis of Double-Layer Box for Marine Reducer

2021 ◽  
Author(s):  
Miaomiao Li ◽  
Qinwen Liu ◽  
Guanghao Dai ◽  
Weifang Chen ◽  
Rupeng Zhu
Keyword(s):  
Path Analysis ◽  
Double Layer ◽  
Transfer Path ◽  
Transfer Path Analysis
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