Troubleshooting Technics to Identify the Airborne and Structure-Borne Noise Content inside an Electric Vehicle

2013 ◽  
Vol 430 ◽  
pp. 297-302
Author(s):  
Marius Cristian Morariu ◽  
Iulian Lupea ◽  
Colin Anderson
Keyword(s):  
Electric Vehicle ◽  
Rotational Velocity ◽  
Sound Field ◽  
Fixed Time ◽  
The Body ◽  
Acoustic Response ◽  
Passenger Compartment ◽  
Transfer Path ◽  
Airborne Noise ◽  
Transfer Path Analysis

An electric vehicle was subjected to on-road acoustic tests. A specific high frequency tone was perceived in a sound field dominated by wind and road noise. The car was instrumented with microphones which measured the noise inside the passenger compartment and with tachometers to record the motors rotational velocity with respect to time. Waterfall diagrams were generated by tracking the spectrums of noise from fixed time samples against the rpm of the motor. The analysis of the diagrams revealed that high orders, like the 24th and 48th were responsible for the sound. These orders represent the acoustic response of the electromagnetic interaction between the stator and the rotor of the electric motor. To analyze the propagation of noise from the source (motor) to the target (driver), a transfer path analysis (TPA), respectively an airborne source quantification (ASQ) were proposed. The TPA focused on the structure borne noise generated by the forces transmitted into the body through the powertrain supports, and the ASQ, on the airborne noise radiated by the surface of the motor and gearbox casing. The conclusion was that the airborne noise is the main contributor to the total pressure level in the passenger compartment, but at lower speeds a strong structure borne noise content is present.

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 Innovations for Airborne Noise Problems with Focus on Pass-By-Noise

2014 ◽  
Author(s):  
Herman Van der Auweraer ◽  
Fabio Bianciardi ◽  
Patrick Van de Ponseele ◽  
Karl Janssens
Keyword(s):  
Path Analysis ◽  
Transfer Path ◽  
Airborne Noise ◽  
Transfer Path Analysis

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.

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.

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.

scholarly journals Comparison between transfer path analysis methods on an electric vehicle

2017 ◽  
Vol 118 ◽  
pp. 83-101 ◽  
Author(s):  
A. Diez-Ibarbia ◽  
M. Battarra ◽  
J. Palenzuela ◽  
G. Cervantes ◽  
S. Walsh ◽  
...  
Keyword(s):  
Path Analysis ◽  
Electric Vehicle ◽  
Transfer Path ◽  
Analysis Methods ◽  
Transfer Path Analysis
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