基于SPH-FEM算法的爆炸焊接界面参数及波形生长机理研究

使用SPH-FEM耦合算法对钛-钢、钢-不锈钢、铜-钢、钛-铝4种常见爆炸复合组合进行了数值模拟，理论分析了材料JC强度方程和SG强度方程的适用应变率范围。探讨了爆炸焊接静态参数基复板厚度和动态参数碰撞速度、动态弯折角对界面温度和压力的影响，借助数值模拟手段研究了界面波形形貌，漩涡和少量飞溅熔化块的生长机理。结果表明，随着复板厚度和碰撞速度的增加，界面温度、压力和波形尺寸明显增加，动态弯折角和基板厚度的改变并不能影响界面温度，界面波形生长遵循着“主逆次顺”运动规律。

Study on Parameters and Wave Growth Mechanism of Explosive Welding Based on SPH-FEM

The SPH-FEM coupling algorithm was applied to simulate four typical explosive composite combinations including titanium-steel, stainless steel-steel, copper-steel and titanium-aluminum. The ranges of strain rate applicable to the Johnson-Cook strength equation and the Steinberg-Guinan strength equation were analyzed theoretically. Besides, the effects of the thickness of the flyer plate and base plate, impact velocity and impact angle on the temperature, pressure and microstructure of the interface during explosive welding were investigated. The growth mechanism of the interface wave, vortex and a small amount of splashing molten blocks were explored through numerical simulation. Results show that the interface temperature, pressure and waveform size increase with the rise in flyer plate thickness and impact velocity, while the peak of interface pressure decreases with the increase in impact angle. The change in the thickness of the base plate cannot directly affect the temperature and pressure of the interface, where the material behaves as an incompressible liquid and reciprocates, producing sinusoidal waveforms, vortex, and splash molten blocks.