Conservatism Implications of Shock Test Tailoring for Multiple Design Environments.

摘要

Specification of a mechanical shock test requires an engineering decision concerning the relationship between the laboratory and field shock environments. Once a method of shock characterization is selected, test conservatism becomes a measure of the degree to which the laboratory test is more severe than the operational environment of the structure being tested. This paper describes a method for analyzing shock conservation in test specifications which have been tailored to qualify a structure for multiple design environments. Shock test conservatism is quantified for shock response spectra, shock intensity spectra and ranked peak acceleration data in terms of an Index of Conservatism (IOC) and an Overtest Factor (OTF). The multi-environment conservatism analysis addresses the issue of both absolute and average conservatism. The method is demonstrated in a case where four laboratory tests have been specified to qualify a component which must survive seven different field environments. Final judgment of the tailored test specification is shown to require an understanding of the predominant failure modes of the test item. (ERA citation 12:050065)