Testing for Random Limit Load Versus Static Limit Load

Abstract

This document is an effort to report the basic test findings in an ongoing quest for understanding how random load factors should be applied to structural components in order to verify the strength of space flight hardware. A Spacelab experiment known as the Atmospheric Emission Photometric Imager (AEPI) was subjected to both an expected flight random environment and the associated Miles' equation equivalent static load. During each of these tests, the fiberglass pedestal was instrumented with 16 triaxial strain gauges around its base. Component strains and invariant stresses were compared. As seen previously in other hardware tests, the stress distribution from the random environment was an order of magnitude below the comparable static stresses. With a proposed data acquisition system, a strain database will be developed that will quantify an empirical relationship between dynamic and static limit stresses. This event will allow a more accurate estimate of launch environment effects on new technology structural components.