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航空整体结构件在铣削过程中,由于材料去除产生的毛坯初始应力重分布和结构刚度演变导致工件发生加工变形。针对这一问题,借助于生死单元技术建立隔框件加工变形预测有限元模型,获得材料去除过程工件变形规律。基于等效弯曲应变能方法,计算加工过程工件刚度变化规律;通过毛坯初始的应力和去除材料产生的弯曲附加应力的叠加分析,结合应力-工件刚度演变特点,借助于材料去除产生的附加力矩分析,构建航空隔框件加工变形数学模型,对隔框工件加工过程变形进行预测分析。将有限元计算结果与数学解析模型计算结果对比,研究表明两种方法获得的加工变形规律相吻合,工件变形特征与去除材料的初始应力状态变化规律相一致。
In the process of milling, the overall structural parts of aviation cause the deformation of the workpiece due to the initial stress redistribution and the structural stiffness evolution of the blank caused by material removal. In response to this problem, the finite element model of machining distortion prediction of bulkheads was established by means of life-death cell technology to obtain the deformation law of the workpiece during material removal. Based on the method of equivalent bending strain energy, the variation law of the workpiece’s rigidity during machining process was calculated. Based on the superposition analysis of the initial stress of the blank and the bending additional stress caused by removing the material, combined with the evolution characteristics of the stress-workpiece rigidity, , Build mathematical model of processing deformation of aviation bulkheads, and predict the deformation of processing of bulkheads workpiece. The results of the finite element analysis are compared with those of the mathematical analysis model. The results show that the deformation laws obtained by the two methods agree well with the laws of the initial stress state of the material.