面内双轴循环载荷下304不锈钢的力学行为

Mechanical behavior of 304 stainless steel under in-plane biaxial cyclic loading

为研究面内双轴载荷下304不锈钢材料的力学行为,运用有限元方法对十字形试样尺寸进行了设计与优化,在自主设计的面内双轴疲劳试验系统上对304不锈钢进行了单轴拉伸、双轴比例加载和非比例圆路径下的力学试验。结果表明,比例加载条件下304不锈钢的棘轮应变累积最小,圆路径下材料的棘轮应变最大,而单轴加载的棘轮应变累积介于比例载荷与圆路径之间。进入棘轮应变稳定增长阶段,圆路径对应的棘轮应变率高于单轴与比例加载,说明圆路径使304不锈钢的损伤失效进程加速。

To study the mechanical behavior of the 304 stainless steel under in-plane biaxial loading,the dimension of the cruciform specimen was designed and optimized by FEM（finite element method）.The tests,including uniaxial tension,biaxial proportional loading and non-proportional circular loading,were conducted by a self-designed in-plane biaxial fatigue testing apparatus.The results show that the accumulation of the ratcheting strain under the biaxial proportional path is the least,the ratcheting strain under the circular path is the most,while the ratcheting strain under uniaxial tension is the medium one.As the ratcheting strain rate becomes stable,the ratcheting strain rates under the circular path are higher than those under the uniaxial or proportional path,which meant that the circular loading can accelerate the damage and failure process of 304 stainless steel.