铜/钢复合管爆炸焊接数值模拟及边界效应

以铜/钢复合管为研究对象，利用AUTODYN有限元软件SPH和ALE法对爆炸焊接过程进行二维数值模拟，分析了焊接动态过程和边界效应问题，并对铜/钢复合管进行了爆炸焊接试验。结果表明，在爆轰波作用下，复管与基管发生倾斜碰撞，碰撞区域压力稳定在10⁷ kPa的数量级，在碰撞区附近出现1条塑性变形带，且复管和基管上的剪切应力相反，界面形态随着爆炸波的传播从直线变为波状，这与试验中获得的T2/316L双金属复合管的实际界面形态一致，说明有限元模型能够有效模拟双金属复合管爆炸焊接过程。数值模拟过程中边缘动态参数值均小于正常值，存在边界效应，增加复管和炸药的长度可以消除边界效应。

Numerical Simulation and Boundary Effect of Explosive Welding of Copper/Steel Composite Pipe

With copper/steel composite pipe as research object, two-dimensional numerical simulation of explosive welding process was conducted through AUTODYN finite element software with SPH and ALE methods. The dynamic welding process and boundary effect were analyzed, and the explosive welding tests of copper/steel composite pipe were conducted. Results indicate that under the action of detonation waves, the composite pipe obliquely collides with the base pipe. The pressure in the collision zone remains stable at the order of 10⁷ kPa, and a plastic deformation band appears near the collision zone. The shear stresses have opposite directions on the base pipe and composite pipe, and the interface morphology changes from straight line to wavy shape with the propagation of explosion wave. This result is consistent with the actual interface morphology of the T2/316L bimetal composite pipe in experiments, indicating that this finite element model can effectively simulate the explosive welding process of bimetal composite pipe. During the numerical simulation process, the dynamic parameter values at the edges are all smaller than the normal values, leading to boundary effects. Increasing the length of composite pipe and explosive can eliminate the boundary effect.