不锈钢焊接凝固裂纹应力应变场数值模拟模型的建立

依据焊接过程的特点，本文把焊接构件分成熔池液相区，固液共存区和固相区三个区域，为了建立焊接凝固裂纹驱动力数值模拟模型，本文详细分析了这三个区域的力学行为，在实测了液态金属的凝固速率和固液态金属的加载卸载响应曲线的基础上着重研究了熔池的变形、固液共存区金属的流变性能和凝固收缩对熔池尾部应力，应变演变过程的影响。最后，采用单元死活的方法解决了熔池的变形问题，采用热、弹、塑性力学方法处理了固相区的应力，

Numerical Simulation Model of Stress-strain Distributions for Weld Metal Solidification Cracking in Stainless Steel

According to the characteristics of welding process, this paper divided the welding joint of a weldment into three zones: the liquid zone in the molten weld pool, the solid-liquid co-existing zone and the solid zone. In order to develop the stress-strain numerical model, the mechanical behaviors of the three zones were analyzed in detail. Moreover, Based on the solid fractions during solidification process and loading-unloading deforming curves of stainless steel SUS310, this paper also studied the effects of deformation of welding pool, the rheologic properties and solidification shrinkage on stress-strain evaluating processes. Finally, the influence of the deformation in the molten-weld pool was eliminated by element rebirth method. Furthermore, the algorithm of the thermal stress/strain for the solid metal formulated on the basis of the incremental thermo-elastoplastic constitutive theory. As a result, a numerical simulation model of stress-strain distributions for welding solidification crack was developed.