Scanning Laser Vibrometer: Evaluation of an Alternative Modal Survey Tool

Abstract

In preparation for the challenges presented by future spacecraft systems, we explore state-of-the-art testing technologies and compare the results to demonstrated, proven methods. A non-contact Polytec PSV-400 scanning laser vibrometer (SLV) is used to characterize the frequency response of a 2 meter reflector in a typical modal test configuration. Complementary measurements are made simultaneously using a conventional accelerometer-based system, and the results are compared to determine the effectiveness of the non-contact tool. The SLV has two distinct advantages that make it an attractive alternative for studying the structural dynamic response of lightweight, high-precision, aerospace structures—increased bandwidth (0.01 Hz-80kHz) and resolution at the nanometer scale. These features are available without modifying the structure, and they do not require labor-intensive preparation of the test article. Typical setup time is less than 1 hour. However, the one-dimensional (1D) SLV system is limited to me...