异质材料点焊过程电热耦合数值分析

Electro thermo Interaction Simulation for Resistance Spot Welding Nugget Process with Dissimilar Materials

以异质材料低碳钢与纯镍电阻点焊为例建立了电阻点焊熔核形成过程的电热耦合有限差分模型。提出了异质金属点焊过程导电、传热耦合作用的模拟方法、接触电阻分析方法和析热机制处理方法。模型中也考虑了随温度变化而变化的材料性能以及边界冷却条件的影响。试验验证表明，数值模拟与试验结果吻合良好，为异质材料点焊基础理论研究提供了一种有效的分析手段。

A three dimensional finite difference electric thermos model for resistance spot welding nugget process of dissimilar materials is introduced.A simulation method of the interaction of electrical and thermal factors is presented.Meanwhile,calculation method of contact resistance and treatment method of heater structure is provided.The influence of the temperature dependent material properties and various cooling boundary conditions on welding process is also taken into account in the modal.An improved method is analysed on dissimilar joint in numerical simulation process.Experimental verification shows that the modal prediction agrees well with the practice.The modal provides a useful means for the analysis of the process of resistance spot welding with dissimilar metals.