铝合金焊接热力耦合及凝固热裂纹敏感性分析

Solidification Crack Tendency and Thermal-mechanical Coupling Analysis of Aluminum Alloy Welding Process

基于热传导方程及热弹性力学理论,建立了铝合金焊接热力耦合模型及有限元求解方法,利用红外线热成像仪实测温度场结果来修正高斯热源模型参数,确定了给定焊接参数的高斯热源模型。将温度场计算结果作为焊接热力计算的输入条件,得到焊接过程热冲击作用下的焊接结构应力应变场。通过计算分析,获得了给定焊接参数的铝合金结构在凝固裂纹敏感温度区间内的应力应变分布规律,并结合裂纹驱动力曲线,分析了不同焊接速度及电流下的凝固热裂纹倾向性。研究结论可以为进一步分析铝合金焊接热裂纹热力学特性提供参考。

Based on heat conduction equation and thermo-elasticity theory, aluminum alloy welding thermal-mechanical coupling model and finite element solution were built. By using temperature field results measured by infrared thermal imager, Gaussian heat source model parameters were corrected. At the same time, Gaussian heat source model and calculation results of temperature field of the given welding parameters were determined. And the results were made to be the input conditions of the welding thermodynamic calculation, which got the welding structure stress and strain fields of the welding structure under thermal shock during welding. Through calculation and analysis, the stress and strain under the given welding parameters within the sensitive temperature range of solidification cracking were obtained. Based on the crack driving force curve of aluminum alloy structure, the solidified hot cracking tendency of different welding speeds and currents was analyzed. The results can provide a theoretical consult for the study of aluminum thermal and mechanical properties of the weld solidification thermal crack.