Experimental and simulation study on low cycle fatigue crack growth and crack tip plastic zone evolution of a marine high-strength steel
The fracture failure of ship structures often results from the combination of low cycle fatigue and cumulative plasticity.In order to study the low cycle fatigue crack growth and plastic zone size of a marine high-strength steel considering cumulative plasticity,the low cycle fatigue crack growth test of a marine high-strength steel CT specimen under tension-tension-cyclic load was conducted according to ASTM E647 standard,and the plastic zone size of crack tip under different crack lengths was measured by DIC method.By introducing Chaboche model,an extended finite element simulation method was established to obtain the plastic zone size at the crack tip for exploring the influence of different load factors on the plastic zone size.Then the effectiveness of the method was verified based on test data.Finally,based on the results of finite ele-ment calculation and Irwin model,a prediction model of plastic zone size at crack tip considering cumulative plastic strain was proposed,and a crack growth rate model based on plastic zone size was established.
plastic zone sizeChaboche combined hardening modellow cycle fatiguecrack propagation
万方数据
维普
