逐层填料建模的多层多道焊残余应力数值分析

Numerical analysis of multi-pass welding residual stresses based on processes chain simulation

基于连续数值模拟技术,在多层多道焊数值建模时,逐步添加每一层焊缝网格模型,进行分步的模拟计算,实现了有效的多层多道焊接热—力耦合有限元计算.利用连续模拟方法与非连续模拟方法,计算分析了多层多道焊试验模型.结果表明,与非连续模拟方法相比,连续建模方法收敛性好,且纵向残余应力峰值结果较传统建模方法更准确.同时,分析了热—力作用下多层多道焊缝的应力演变历程,揭示了多重热循环作用下焊缝纵向残余应力的变化过程.

Based on processes chain simulation technology,a gradually added filler element method was applied for modeling multi-pass welding and the simulation was achieved step by step with coupled thermal-mechanical finite element method.A research part of multi-pass welding was simulated by both the chain simulation technology and the traditional method.To compare the two simulations,convergence for the chain simulation technology is better and its results of longitudinal residual stresses are more accuracy.Meanwhile,the stress evolution history under the thermal-mechanical activities of multi-pass welding was analyzed,and the principle of longitudinal stresses changing under multi-thermal cycles was revealed.