高强轨道钢双轴压-扭棘轮行为的实验和模拟

EXPERIMENT AND SIMULATION ON THE BIAXIAL COMPRESSION-TORSION RATCHETING BEHAVIOR OF HIGH STRENGTH RAIL STEEL

在室温下对高强轨道钢进行了单轴和非比例双轴压-扭循环变形行为的实验,讨论了不同加载路径对轨道钢棘轮变形行为的影响。结果显示:该轨道钢呈现出明显的循环软化效应和压缩方向的棘轮行为,且棘轮行为的演化表现出强烈的加载路径相关性;在椭圆路径下,棘轮应变较其他四种路径更小。进而建立了基于Abdel Karim-Ohno非线性随动硬化律的非比例多轴循环棘轮本构模型,并通过在随动硬化和各向同性软化律中引入非比例因子来考虑非比例路径对双轴压-扭棘轮行为的影响。实验结果和模拟结果的对比表明:该本构模型能够较好地模拟高强度轨道钢的非比例双轴压-扭棘轮行为。

The cyclic deformation behaviors of high strength rail steel were experimentally investigated under uniaxial and non-proportional biaxial compression-torsion cyclic loading at room temperature. The effects of loading paths on the ratcheting behaviors of the high strength rail steel were discussed. The results show that the high strength rail steel exhibits obvious cyclic softening effects and ratcheting behaviors in the compression direction. Moreover, the evolution of ratcheting behaviors depends strongly on loading paths, and the ratcheting strain under an elliptical loading path has the minimum value among five typical loading paths. At the same time, a non-proportionally multiaxial cyclic plasticity constitutive model can be developed based on the Abdel Karim-Ohno non-linear kinematic hardening rule. In addition, the effects of loading paths on ratcheting behaviors were addressed by introducing a non-proportional factor into the kinematic hardening and isotropic softening rules The comparison of simulations with experiments demonstrates that the extended model can rationally describe the non-proportionally biaxial compression-torsion ratcheting behaviors of the high strength rail steel.