CTAG has developed a new facility for noise measurement and objective assessment under multi-axis vibration. The new facility consists of an Anechoic Chamber coupled to an MTS High Frequency Multi-Axis Simulation Table, which allows for 6DOF excitation of isolated components up to 500Hz. The operational noise of the electrohydraulic shaker is extremely low and the anechoic chamber avoids unwanted reflections and isolates the measurement area from external noise and vibration. Under such conditions, sound quality metrics can be computed from the measured signals in order to objectively evaluate the noise level of the components.
Although the main focus of the new facility is the acoustic measurement and objective rating of S&R of automotive components, three other applications have been considered in its design:
- Full vehicle acoustic measurements: the size of the anechoic chamber means a whole vehicle can be brought in and tested for acoustic measurements such as operating noise of the vehicle components, acoustic isolation of the vehicle openings, car audio equipment analysis, etc.
- Vibroacoustic analysis of structures: the anechoic chamber is equipped with an acoustically and vibrationally isolated casting plate. The component can be excited with a modal hammer or modal exciter while the response is measured through omnidirectional microphones. This allows for measuring the relationship between vibration input and acoustic output on automotive samples, and correlating the results with the modal behaviour of the structure.
- Operating noise of components: the casting plate allows for mounting isolated components, such as the electric window system, radio operation, unloaded electric motors, etc., and analysing their operating noise.
As a result, a highly versatile facility is available to the automotive industry for objective vibroacoustic analysis and troubleshooting, using state-of-the-art multi-axis vibration and noise analysis equipment, with the consequent reduction in the development time.