基于蠕变理论与有限元仿真的轨道交通车辆铝合金冲压件滞后回弹研究

滞后回弹是影响冲压件形状精度的关键因素.针对复杂工况下冲压件滞后回弹的预测与验证问题,提出了一种基于蠕变理论与有限元仿真方法.以轨道交通车辆司机室补强板为例,采用单轴拉伸试验测定了不同应力状态下5083-O铝合金材料的蠕变行为,并选用幂函数本构模型进行蠕变参数拟合;采用数值模拟手段分别建立了冲压成形、卸载回弹及滞后回弹...

Time-dependent Springback of Rail Transit Vehicle A1 Stamping Parts Based on Creep Theory and FE Simulation

Time-dependent springback is a critical factor affecting the shape accuracy of stamping parts.Aiming at the time-dependent springback prediction and validation of stamping parts under complex working conditions,a method based on creep theory and FE simulation is proposed.Taking railway vehicle reinforcing plate as the research object,the uniaxial tensile test is conducted to obtain the creep behaviors of AL 5083-O under different stress conditions;then,the power function constitutive model is used to fit the creep parameters;finally,simulation models of stamp forming,instantaneous springback and time-dependent are built respectively by means of numerical simulation.As a result,the stress evolution and shape error data in different stages are obtained.On this basis,the forming experiment is implemented.and the noncontact optical measuring equipment is used to measure the time-dependent springback in two weeks,the data are compared with simulation and theoretical results,This research shows that the time-dependent springback distribution trend is consistent with the simulation and the experiment,the maximum error between them is only 0.069 mm.The maximum time-dependent springback is 0.32 mm,that could meet the welding requirements with manual grinding in actual production process.