Research on the Fatigue Crack Growth Behavior of a Zr/Ti/Steel Composite Plate with a Crack Normal to the Interface

The current work reveals the influence of loading parameters on the crack growth behavior of a Zr/Ti/steel composite plate with a crack normal to the interface by using an experiment and the finite element method. The Chaboche model was first used to study cyclic plastic evolution in composite materials. The results reveal that an increase in F_max, F_m, and F_a can promote da/dN; meanwhile, an increase in R will reduce da/dN. The plastic strain accumulation results indicate that F_m mainly contributes to the tensile strain and compressive stress after the first cycle. Additionally, F_a increases the stress range and compression stress and greatly improves the plastic strain accumulation degree in subsequent loading cycles. The F_max can significantly increase the stress amplitude and plastic strain accumulation level. When R increases, the plastic strain accumulation increases a little, but the stress amplitude and compression stress decrease greatly. Furthermore, it is also found that the elastic-plastic mismatch also affects the plastic evolution, that is, strengthening or weakening the effect of the loading parameters.