Strain estimation for low cycle dynamic loads

The most effective way to avoid the overestimation of low cycle dynamic load cases is to shift the design basis from limitation of stress to the limitation of strain. As the high effort needed for step-by-step numerical integration of non-linear structural response is prohibitive methods for approximate strain evaluation are inevitable. The fundamental of a strain estimation method based on the concept of energy dissipation and structural hardening as functions of strain range are described. The need for nonlinear information is reduced either to a limited number of quasistatic non-linear computations or to a certain knowledge of the yield behaviour of structural members. (orig.)