预拉伸对铝合金桶体焊接残余应力和变形影响的数值模拟

利用ANSYS软件模拟在有预拉伸应力和无预拉伸应力作用下，厚度为4mm的7075铝合金试板的焊接。结果表明：预拉伸焊接法可有效减小铝合金薄板焊后的残余应力和变形。预拉伸应力抵消了部分焊接区热膨胀产生的压缩应力，从而减小了压缩塑性变形，进而减小了冷却时焊接区域的拉伸应力，相应地远离焊缝区域的压缩应力也随之减小。

The Effect of Pre-tensile on Aluminum Alloy Welding Residual Stress and Strain Were Respectively Simulated by ANSYS

The thickness of 4mm barrel of 7075 aluminum alloy welding tests under prestretching stress and non-predrawing were respectively simulated by ANSYS.The results show that welding residual stress of aluminum alloy barrel was reduced remarkably by pre-tensile welding method.Compressive stress caused by thermal expansion in thermal area was offset partially by pre-tensile stress and compression plastic deformation was also decreased.Thereby,the tensile stress over welding zone was reduced when cooled and the compressive stress far from weld seam was diminished accordingly.