(西安交通大學(xué) 材料科學(xué)與工程學(xué)院，西安 710049)
摘 要: 針對鋁合金5A12有限薄板鎢極惰性氣體(TIG)焊接過程存在非準(zhǔn)穩(wěn)態(tài)的特點(diǎn)，提出了考慮熱源預(yù)熱作用及移動效應(yīng)的二維高斯熱源修正模型，并采用修正的二維高斯熱源模型對其焊接熱過程、焊接殘余角變形和縱向殘余應(yīng)力進(jìn)行數(shù)值模擬及研究，同時(shí)比較數(shù)值模擬及實(shí)驗(yàn)結(jié)果。實(shí)驗(yàn)結(jié)果表明：利用修正的二維高斯模型能較好地反映有限薄板的焊接特點(diǎn)，所計(jì)算的接頭熔合區(qū)形狀、熱循環(huán)曲線與實(shí)驗(yàn)結(jié)果吻合良好。焊接殘余角變形及焊接縱向殘余應(yīng)力也得到了與實(shí)驗(yàn)值較接近的模擬結(jié)果。利用此修正的二維高斯模型可提高焊接溫度場、焊接縱向殘余應(yīng)力與變形數(shù)值模擬的準(zhǔn)確性。
關(guān)鍵字: 熱源模型；有限尺寸；預(yù)熱；殘余應(yīng)力；殘余變形
（School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China）
Abstract:The characteristics of the quasi-steady-state during tungsten inert gas (TIG) welding process on 5A12 aluminum alloy sheet with limited size were analyzed. The welding process, residual angular deformation and longitudinal residual stress were numerically simulated and studied using the modified two-dimonsional Gaussian heating source model. The numerical simulation results were compared with experimental results. The results show that the numerical results by the modified two-dimensional Gaussian model reflect well the limited plate welding characteristics. The shape of joint fusion zone and thermal cycle curve calculated agree well with the experimental results. And the welding residual deformation and longitudinal welding residual stress are closer with the experimental value of the simulation results. The welding temperature field, welding longitudinal residual stress and deformation can be simulated accurately using the modified two-dimensional Gaussian model.
Key words: heating source model; limited size; preheating; residual stress; residual deformation
