Development of Finite Element Program of Three Dimensional Thermal-Elastic-Plastic Analysis and Its Application to Assembly of a Compressor by Welding.
Development of Finite Element Program of Three Dimensional Thermal-Elastic-Plastic Analysis and Its Application to Assembly of a Compressor by Welding.
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三维热弹塑性分析有限元程序的开发及其在压缩机焊接装配中的应用。
DOI：
10.2207/qjjws.13.628
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Y. Ueda
中科院分区：
文献类型：
--
作者：
M. Yuan;Jianhua Wang;H. Murakawa;Y. Ueda
编制了三维热弹塑性有限元分析程序。由于焊接过程中的几何非线性和材料非线性的温度依赖性，如何保证计算精度并得到稳定的解是一个重要的问题，特别是在高温阶段。对影响计算精度和收敛性的因素进行了研究。结果表明，在弹性向塑性转变、卸载阶段、材料性质随温度快速变化阶段等剧烈变化阶段，数值计算误差较大。用实体单元求解薄板或薄壳弯曲问题时，数值锁定现象也会影响求解结果，本文采用所开发的程序对压缩机过盈装配和塞焊两种模型的残余变形进行了分析。在程序中采用了适当的方法，以提高数值分析的精度和收敛性。其中一种方法是在力学状态和材料性能发生剧烈变化的阶段，对应变增量采用加权因子。为了防止堵转现象，对压缩机气缸部分采用了选择性减缩积分法。将计算的变形与测量值进行比较。结果表明，引入所提出的方法后，可以获得良好的一致性，开发的程序可以提供令人满意的解决方案。研究了焊接工艺条件对压缩机组装件偏心的影响。
A finite element program for three dimensional thermal-elastic-plastic analysis was developed. Because of the geometrical nonlinearity and the temperature dependent material nonlinearities during welding, it is an imprortant problem how to ensure the computing accuracy and to get the stable solution, especially at a high temperature stage. Factors that may influence the accuracy and the convergence of computation were investigated. The results show that the stages with drastic change, such as transition from elastic to plastic, unloading stage, and stage in which material properties vary rapidly with temperature, suffer from the numerical error. When the solid elements are used for the bending problem of a thin plate or a shell, numerical locking phenomenon may also influence the solution.Residual deformations were analyzed by the developed program for two models taken from shrinkage fit process and plug welding process of a compressor. In the program proper methods were introduced to improve the accuracy and the convergence of numerical analysis. One of them is to use weight factors for strain increment in the stages with drastic changes in mechanical status and material properties. In order to prevent the locking phenomenon, the selective reduced integration method was adopted to the cylinder part of the compressor. The calculated deformations were compared with the measured values. The results show that good agreement can be obtained after introducing the proposed methods and that the developed program can provide satisfactory solutions. The influences of the welding conditions upon the eccentricity of assembled components in the compressor were also investigated.