Theory of scattered fracture at the complex stress state

Abstract

Examination of the fracture process during uniaxial tension or compression is of prime importance in determining basic fracture rules of materials. However, we should now extend the scope of our investigations since a multitude of structures and load-bearing parts are subject to severe conditions of the complex stress states and loads. This chapter considers a phenomenological model to long-term strength of a solid body. The main concept is based on the gradual accumulation of damage in the material during the fracture process in the complex stress state. Since the accumulation of defects is a time process and depends on the type of the stress state, it is possible to calculate the damage accumulation within the framework of the proposed theory, when the type of the stress state varies with time, i.e., to consider the effects of complex (nonproportional) loading.