大型复杂框架结构焊接变形与应力控制仿真

针对大型复杂结构件有限元计算效率低下的问题，提出了分段移动温控体热源高效算法，并将该算法应用于挖掘机中框架非连续焊的分层逐项优化中，对分段移动温控体热源模型和逐点移动双椭球热源模型的计算效率进行了对比。结果表明，取对称焊与跳焊相结合的焊接方式所得到的焊接残余应力和角变形量最小，左右两侧立板处焊接残余应力峰值相较于原工艺方案，降幅率分别为38.46%和42.13%，降低效果显著；分段移动温控体热源模型与逐点移动双椭球热源模型模拟结果相比，两者得到的变形量变化趋势一致，计算精度相当，但前者计算效率显著要高。将模拟结果与测量结果进行对比，两者高度一致，验证了热源模型及优化工艺的准确性。

Welding Deformations and Stress Simulations Control of Large-scale Complex Structures

Aiming at inefficiency problems of finite element calculations of a large-scale complex structure, this paper put forward piecewise mobile body heat source temperature control algorithm, applied to the hierarchical optimizations of discontinuous welded frames in an excavator, and compared calculation efficiencies of segmented moving temperature control body heat sources and point by point moving double ellipsoid heat sources. The results show that welding residual stresses and angular deformations were minimized by using welding procedures of symmetrical welding and skip sequence welding. The peak drop rates of welding residual stresses on both the left side plates and the right side plates reach to 38.46% and 42.13% respectively. Also the welding residual stresses decrease obviously. Compared with the simulation results of segmented moving temperature controlled body heat sources and point by point moving double ellipsoid heat sources, it is indicated that the two methods have the same trends and the calculation accuracy is close, but the computational efficiency is improved remarkably. The simulation results are compared with the measured results, which verifies the accuracy of the heat source model and the optimumprocess, because the two are highly consistent.