爆炸法消除焊接接头残余应力的数值模拟

利用非线性动力有限元法对爆炸处理消除焊接接头残余应力的全过程进行了数值模拟。首先，采用温度场与位移场的间接耦合方法计算了钢板对接焊的焊后冷却及残余应力的生成过程，求得焊接接头处由高温冷却到室温由于变形受到阻碍而产生的不均匀的残余塑性变形和应力。然后，在焊缝区引入移动的爆炸载荷，计算了爆炸波作用下该钢板焊接接头附近应力的变化。计算结果表明，爆炸处理可引起板内应力的重新分布，从而有效地释放超过塑性极限的残余应力。利用炸药爆炸消除大型焊接结构残余应力是一种经济有效的方法，本文的数值模拟为研究炸药爆炸消除焊接结构残余应力的机理提供了有力的工具。

Numerical Simulation on the Relief of Welding Residual Stress Through an Explosive Treatment

The whole process of the relief of the welding residual stress through an explosive treatment is simulated by using the nonlinear dynamic finite element method. First, the cooling process of a butt-welded steel plate after welding is simulated and the generation of residual stress in this course is calculated by using the indirect iteration method of coupled temperature field and stress field. When the high temperature of the weld joint drops down to the chamber temperature, asymmetric residual plastic stress and strain are aroused since the deformations are restricted by the surrounding area. Then, a movable explosive loading is applied to the weld line to simulate the blast of a strip of detonator laying on it. In this way, the variation of the residual stress in the whole plate is analyzed numerically. The numerical results indicate that the explosive treatment can lead to a redistribution of the welding residual stress, which relieve the large residual stress effectively. The explosive method is an economic and efficient way to reduce the residual stress in large-sized structures. This research supplies a powerful tool for the investigation of the mechanism of the explosive treatment.