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采用显式动力学分析软件ANSYS/LS-DYNA对激光冲击加载过程进行模拟,通过调整激光冲击参数,探究其对7050铝合金表面形成“残余应力洞”的影响;将模拟结果与X射线应力分析仪测得的试验结果进行对比,并分析两者的误差来源。结果表明,激光功率密度、脉宽的增加会加剧“残余应力洞”现象,光斑直径的增加会抑制“残余应力洞”现象;当激光功率密度为1.98 GW/cm~2时,模拟与试验有较好的一致性;当激光功率密度提高至2.77 GW/cm~2时,激光能量的增强加剧了冲击区域近表面的塑性变形,引发了模拟与试验的误差;当激光功率密度进一步提高至4.07 GW/cm~2时,冲击区域近表面会形成亚晶粒,甚至晶粒细化形成纳米晶,使冲击区域表面残余应力均匀分布。
The laser shock loading process was simulated by explicit dynamic analysis software ANSYS / LS-DYNA. The laser shock parameters were used to investigate the effect of laser shock on the “residual stress hole” on the surface of 7050 aluminum alloy. The simulation results were compared with X-ray Stress analyzer measured the test results were compared and analyzed the source of the error between the two. The results show that the increase of laser power density and pulse width aggravates the “residual stress hole” phenomenon. The increase of spot diameter suppresses the “residual stress hole” phenomenon. When the laser power density is 1.98 GW / cm ~ 2, When laser power density increases to 2.77 GW / cm ~ 2, the laser energy intensifies aggravates the plastic deformation near the impact area, which leads to the error of simulation and experiment. When the laser power density Further increase to 4.07 GW / cm ~ 2, the impact near the surface area will form subgrain, and even grain refinement to form nanocrystals, so that the impact area surface residual stress evenly distributed.