1. Mechanical Engineering Department,Zhejiang Industry Polytechnic College,Shaoxing 312000,Zhejiang, China 2. Modern Manufacturing Engineering Institute,Zhejiang University,Hangzhou 310000,Zhejiang, China 3. College of Mechatronics Engineering,University of Electronic Science and Technology,Chengdu 611731,Sichuan,China
Abstract:The behaviour of fatigue crack growth was significantly changed by the closure behavior of fatigue crack. The crack closure behaviour of 316L stainless steel was investigated by combining the loading test and the numerical simulation to study the dynamic crack propagation. The fatigue crack growth experiment included the constant amplitude loading and single tensile overload. The crack closure behaviour and the crack growth rate in different propagation period were studied with different crack length, stress ratio and overload. The intrinsic mechanisation between the single tensile overload and the crack closure was discussed. An improved model to calculate the effective stress intensity factor range was applied based on the theory of crack closure and the calculated results. The prediction formulation of crack growth rate was fitted about the 316L steel.