A STUDY OF THE DYNAMIC STRESS-CONCENTRATION FACTORS OF A FLAT-PLATE FOR SEA APPLICATIONS

Statistical Energy Analysis (SEA) methods have been used to obtain the mean square vibrational energy levels of connected structures under c ertain conditions of coupling and excitation by random, uncorrelated f orcing. Simple relationships between spatially averaged energies or ve locities to stress and strain have been developed. However, the predic tion of spatial variations in dynamic stress distribution at boundarie s and discontinuities is more difficult and very few studies have been made in the SEA context. This paper first compares SEA predicted spat ially averaged mean square stress to that of a FEA model of a simple t wo-plate system. Then it studies the behaviour of the dynamic stress c oncentration factors at the clamped boundary and also at the corner of a square hole in a hat plate at different frequency ranges using FEA models. The method used here is particulary useful for SEA application s, the stresses being normalized to unit power input. Certain assumpti ons for stress prediction at boundaries from SEA derived uniform stres ses are also verified. (C) 1998 Academic Press.