The goal of this paper is to provide a method for airborne source description of the EC and to determine the airborne sound contribution at the driver’s ear. The radiation of the EC was approximated by six acoustic monopoles emitting a volume acceleration. The characterization was conducted with the help of noise transfer functions (NTFs) and operational measurements in an anechoic chamber. Volume acceleration sources were used to measure the NTFs. The validation of the source identification was performed in a changed environment and a vehicle.
Before performing a transfer path analysis (TPA), the engineer needs to think about the right modeling of the source’s interface with the receiver. In practice, the vibration transfer from the source to the receiver is often modeled with three translational forces in each connection point. Mechanically this corresponds to a ball joint connection, which cannot transfer any moments. This study compares different complexities of interface descriptions on the industrial example of an electro-magnetic roll control (ERC) in a passenger car.
Hydraulic testing machines can be used to obtain frequency dependent dynamic stiffnesses of rubber isolators in translational degrees of freedom (DoF). Alternatively, dynamic substructuring based methods can be used. Results of two substructuring methods will be compared to those from a hydraulic machine.
E-compressor airborne NVH Airborne sound predictions in vehicles with the help of component-based transfer path analysis
Due to the lack of masking noise from combustion engines in electric vehicles, the noise of auxiliary components is becoming a relevant topic. One of these components is the electric refrigerant compressor (ERC). This paper addresses the airborne sound transmission of the compressor, using the methods of component-based transfer path analysis (TPA).
Currently two ISO standards are proposed for source characterisation. In this paper it is shown how the different approaches can be derived and compared using the general framework for Transfer Path Analysis (TPA).
A benchmark structure for validation of Experimental Substructuring, Transfer Path Analysis and Source Characterisation techniques
This paper presents a practical study on popular Experimental Dynamic Substructuring topics. A series of substructures is designed of such complexity to fit in right between “real life” structures and “academic” structures.
This paper presents a Transfer Path Analysis (TPA) method to predict the transmission of steering gear vibrations of BMW vehicles in a multi-kHz range. The blocked-force TPA concept is used.
Component-based Transfer Path Analysis allows us to analyse and predict vibration propagation between an active source and passive receiver structures. The forces that characterise the active source are determined using sensors placed on the connected passive substructure.
Transfer Path Analysis (TPA) designates the family of test-based methodologies to study the transmission of mechanical vibrations. Since the first adaptation of electric network analogies in the field of mechanical engineering a century ago.
This paper presents a comparison of two component Transfer Path Analysis methods to predict the transmission of steering gear vibrations into the vehicle.
This page provides an accessible overview of Dynamic Structuring, the interface conditions required and the applications of Dynamic Substructuring in different domains
Validation of Current State Frequency Based Substructuring Technology for the Characterisation of Steering Gear–Vehicle Interaction
This paper presents a validation study of several experimental Frequency Based Substructuring (FBS) techniques that were developed recently. Advances in the techniques up to 2009 were already applied and validated using the rear axle differential – vehicle interaction as a test case.
An improved methodology for the virtual point transformation of measured frequency response functions in dynamic substructuring
Crucial in Dynamic Substructuring is the correct definition of the interfaces of the subsystems and the connectivity between them. Although this is straightforward practice for numerical finite element models, the experimental equivalent remains challenging.
In this paper a vision on substructuring methods is proposed, by recalling important historical milestones that allow us to understand substructuring as a domain decomposition concept.