Analyzing and controlling distortion of aircraft aluminium alloy structural part in NC machining
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摘要: 以飞机机翼翼肋铝合金结构件这一典型易变形的零件为例,研究数控加工变形情况及其影响因素,主要研究残余应力对加工变形的影响.采用理论建模、有限元分析和实验验证相结合的方法分析和对比数控加工中零件变形情况;分析了工件内残余应力分布,用有限元软件提供的热机耦合功能,以温度场模拟施加铝合金的残余应力分布;分析和模拟了去除材料对工件变形的影响;用经过改进的顺序静态单元生死方法进行切削过程的仿真和改进,并对仿真所得的零件变形量与实际加工测量结果进行了比较,验证了分析方法和所建立模型的有效性;最后提出了控制数控加工变形的解决方案.Abstract: NC machining distortion and the reason which leads to machining distortion were studied by analyzing the typical aircraft wing rib aluminium alloy structural part on which distortion often occurs. The part NC machining distortion was analyzed and compared by using the methods of theoretical model, finite element analysis and milling experiment. Residual stress distribution was analyzed in the part. Temperature simulation was added to the residual stress distribution of aluminium alloy by using thermal-mechanical coupling analysis of the FEM(finite element method) software. The influence on part distortion by cutting material was analyzed and simulated. The cutting process was simulated and improved through using the improving static elements deactivation method. Simulation distortion result of machining process was compared with the milling experiments and practical experience data. The validity of the analysis method and the finite element analysis model was verified. Several methods which can be used to predict and control machining distortion were proposed.
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Key words:
- numerical control machining /
- distortion /
- residual stress /
- simulation /
- finite element method 1 问题提出
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