热冲击下机械结构非线性热力耦合模型的建立

Research on Nonlinear Thermal-mechanical Coupling Model of Mechanical Structure under Heat Shock

在热弹性耦合理论的基础上 ,考虑热冲击作用下弹塑性变形功的影响 ,建立了非线性热力耦合有限元模型。其中包括 :基于能量守恒原理建立的非线性瞬态温度场模型 ;考虑几何非线性及材料非线性的位移场模型 ;求得改进应力场的最小二乘法模型。基于FEPG软件平台进行了实例求解 ,计算结果表明了此耦合模型的有效性。此模型的建立 ,拓展了热力耦合理论的应用范围 ,具有较高的工程实用价值。

Based on the coupled-thermo-elastic theory and considering the influence of elastic-plastic deformation work, a finite-element model for coupled-thermal-mechanical analysis is established under the condition of pure heat shock. The coupling model includes three equations: the nonlinear transient temperature-field equation founded on principle of conservation of energy, the displacement-field equation for geometrical and material nonlinearity, and stress-field equation introducing least square method to improve calculation precision. A detail computation of an example is performed with FEPG finite element program generator software. The numerical results demonstrates the efficiency of the coupling model, which broadens the applied range of coupling thermal-mechanical theory from elasticity to plasticity.