基于热-力耦合法的高速车地板焊接变形数值模拟

基于热-力耦合的有限元法,对高速车地板大型复杂铝合金挤压中空型材结构的拼焊过程进行了数值模拟.为了提高计算精度,试验测试了随温度变化的材料动态力学性能参数及热物理参数,并采用移动双椭球体热源模型模拟MIG焊接热源.对多个高速列车地板结构的焊后挠曲变形进行了现场测试.结果表明,模拟计算结果与测试数据具有很高的吻合度.基于热-力耦合的有限元法并将材料动态高温性能参数带入模拟计算的方案能够为大型复杂结构的焊接变形预测提供高效、高精度的技术手段,为目前结构的制造工艺改进及新产品的开发提供数字化的研究平台.

Numerical simulation on as-welded deflection of high speed rail floor based on thermo-mechanical coupling

Based on the thermo-mechanical coupling analysis of FEM,the joining process of high speed rail floor was studied,which was welded by seven pieces of large-scale hollow extruded shape of aluminum alloy.To enhance the calculation precision,the mechanical and thermal-physical properties of the aluminum alloy and its filler metal were tested between room temperature and their melting points,moreover,the moving double-ellipsoid heat source was employed to simulate the metal-inert gas welding.The measured as-welded deflection data of ten real rail floors at the production site was highly coincident with the numerical simulation results.The results proved that,the thermo-mechanical coupling analysis and the dynamic material properties were two essential factors in the high precision simulation of high speed rail floor,which could lay a digital workplace for the improvement of the current process and further development of the new-type assembly.