A change in the deformation mechanism with a monotonous change of the load parameter

Abstract

This work analyses the deformation of high-loaded structures for problems of strength and safety. Determining the load safety factor typically requires a series of calculations with successively increasing loads, up to fracture. In cyclic loading, each calculation is a numerical modeling of the structure behavior during several (or several tens) cycles up to stabilization to estimate the damage accumulated during one stable cycle. In multi-parameter loading, different load combinations may cause different mechanisms of structural deformation (i.e., different distributions of plastic strains and their velocities in the structure) with different consequences for the structure, thereby requiring different safety factors. At one-parameter loading, the assumption that the deformation mechanism remains the same for different load levels could reduce the required number of calculations. This article presents examples proving that this assumption could lead to incorrect results and requires careful verification.