Vehicle Testing and NVH Program support

Projects include initial subjective and objective benchmarking, vehicle-level and system/component-level target setting, NVH troubleshooting and development to achieve programme targets, and launch support.

Ensuring the acoustic and vibration performance of a vehicle is hugely challenging and requires expertise in a range of noise vibration harshness (NVH) performance domains. To achieve fast and efficient response, automotive OEMs sometimes choose to outsource the responsibility for NVH vehicle integration.

We have worked with a number of customers where we have taken full responsibility for development of all aspects of noise and vibration in the vehicle programme and have acted as the noise and vibration lab.

Activities range from initial subjective and objective benchmarking, vehicle-level and system/component-level target setting, NVH troubleshooting and development to achieve programme targets and launch support.

Activities include:

Benchmarking activities to aid in vehicle-level target setting, along with cascading of targets down to the system and component-level.
Power train NVH responsibilities (acoustic and structural development, mount development, rigid-body modes, modal coupling, intake/exhaust assessments, etc.)
Road noise development (structural/acoustic troubleshooting and countermeasure development)
Wind noise development (noise source identification, leak path studies, acoustic package optimization, and countermeasure development)
Acoustic package optimization to achieve programme targets, utilizing both conventional methods as well as advanced acoustic imaging techniques to streamline evaluation time
Body structure dynamic-mode assessments against programme targets to aid troubleshooting efforts and identify potential concern areas for power train noise, road noise, etc.
Support through to launch, including key driving evaluations by management and press events

Here are some projects and project elements we have worked on with customers:

Experimental testing for and finite element analysis (FEA) correlation of acoustic cavity and trim

A software and services company working with an automotive OEM requested that we assess (experimentally) all the cabin acoustic cavity modes in a vehicle, up to 150 Hz, to achieve better correlation between test and Computer-aided engineering (CAE) analysis.

Experimental Testing for FEA Correlation of Acoustic Cavity and Trim

Stationary acoustic and vibration measurements were conducted in a hemi-anechoic chamber. Vehicle body panels were instrumented with accelerometers and several microphones were positioned in the cabin. For the acoustic artificial excitation tests, a low-frequency volume velocity source was placed behind the rear seats. For the structural artificial excitation tests, a rear wheel was removed and a shaker positioned to excite at a rear suspension attachment point. Measurements were made at customer-defined locations with different trim configurations, from fully trimmed to completely bare. Complete datasets of acoustic, structural and vibro-acoustic transfer functions (V/F, P/F, V/Q, P/Q) were taken for each trim configurations and provided to the CAE team for correlation.

Integration of an electric power train in a SUV

An automotive OEM needed help to integrate an electric power train into an existing vehicle architecture. The project included benchmarking activities within the electric vehicle market with targets that cascaded down to the component-level. Performance relative to these targets was tracked throughout the development cycle, central issues were identified, and countermeasures were developed, evaluated, and implemented in cooperation with the OEM’s NVH team. Key development activities included power train mount development, acoustic package optimization, road and wind noise treatments, and accessory NVH performance. Programme support continued through to post-launch with successful public reviews. Our staff was also responsible for management of all day-to-day and long-term NVH activities in support of the vehicle development, being on-site at the OEM for over two years.

Vehicle NVH program support

An electric vehicle automaker needed NVH programme support for a vehicle programme from conception through the development process and on to launch. Initial targets were established from vehicle benchmarking and assessed throughout the programme using defined standardized tests. We measured static and operational acoustic and vibration data in a hemi-anechoic chamber and on-road at the customer’s US facilities. Multiple techniques, such as source path contribution, array-based and multi-coherence measurements and analysis, as well as troubleshooting, were used throughout the development process. Our engineers functioned as the customer’s NVH group throughout the project, from early target setting through to vehicle launch.