The modal testing experiment presented here is performed by an automobile manufacturer using ModalVIEW software and National Instruments DSA hardware as the modal testing and analysis tool. The analysis result is used to verify their automotive design.

Experiment scenario

The testing object is a car body in white structure:

The car body in white structure is excited by two shakers. ModalVIEW modal analysis software provides MIMO FRF computation and advanced modal analysis method based on mode stabilization diagram to extract modes from FRF measurements. National Instruments 24-bit module PXI-4498 is used to guarantee the accurate measurement of weak vibration signal of measured points far away from excitation point.  

System configuration

In this modal testing experiment, the following software and hardware are used：

1．ModalVIEW R2 Software.

2．NI DSA System (PXI Chassis PXI-1042 Controller PXI-8106, 16 channel DSA module PXI-4498)

3．Tri-axial accelerometer (Kistler 8690C50).

4．Electromagnetic shaker.

Analysis results

Modal analysis for the structure is finished with ModalVIEW’s advanced mode estimation method based on mode stabilization diagram from 232 measured FRF data. Part of the mode shapes are displayed as following :

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