长脉冲与连续激光联合作用下铝合金的应力场仿真  

Stress Simulation of Aluminum Alloy Irradiated by Long Pulsed Laser and Continuous Wave Laser

作　　者：肖婧[1] 何衡湘[1] 夏惠军[1] 

机构地区：[1]西南技术物理研究所,四川成都610041

出　　处：《中国激光》2013年第8期94-99,共6页Chinese Journal of Lasers

摘　　要：为了给组合使用长脉冲与连续激光作用模式参数的选择提供依据,利用有限元软件ANSYS建立了组合激光辐照2A12铝合金的三维参数化有限元计算模型,进行了不同组合参数下温度场和应力应变场的计算。模拟结果表明,使用连续激光预热能显著增强长脉冲激光的作用效果。预热时间越长,材料的屈服时间(即从施加脉冲激光到材料发生塑性屈服的时间)越短,塑性变形以及屈服范围越大。在占空比为10%的长脉冲串作用下,导热系数较大的铝合金在脉冲间的温度和塑性应变积累并不明显。当激光功率在104 W/cm2量级时,对于同一参数的长脉冲激光,连续激光的预热时间比其功率密度对铝合金的影响更大。A three-dimensional finite element model is established to perform the thermo-elastic-plastic analysis on stress and deformation of 2A12 aluminum alloy irradiated by lasers with different parameters in ANSYS software. The results show that with an assistant continuous wave （CW） laser to preheat the material, the effect of long pulsed laser efficiently increases with the increase of preheat time, materials yield time shortens, plastic deformation and yield zone augrrent. Irradiated by tong pulsed laser with duty cycle of 10%, the temperature rise and deformation accretion of 2A12 aluminum alloy between pulses are not significant because of its high thermal conductivity. Increasing the preheat time is a more effective method than the power density increasing of CW laser to increase the plastic damage of material irradiated by the same long pulsed laser when their power densities are at 10^4 W/cm^2 level.

关 键 词：激光技术 双光束 铝合金 预热 塑性屈服 应力场 

分 类 号：O532.25[理学—等离子体物理]