Improvement of Response Spectrum Specifications in Dynamic Testing

Abstract

Required response spectra (RRS) are commonly used as dynamic-test specifications in product qualification. RRS specification for a product is normally developed by considering the operating environment of the product. This paper presents a technique to improve the RRS specification for a qualification test by employing available dynamic information on the test object. Specifically, a model of the test object subjected to support-motion inputs is employed. In practice, a model for the test object can be conveniently determined by experimental modal analysis or by the finite element method. The method presented in this paper may be viewed as a way to apportion the energy of test excitations among input locations of a test object in order to optimize a test objective. The underlying theory of the method of modifying a specified RRS is outlined and the computational steps of the method are given. A numerical example is presented to illustrate the use of the method.