复合材料夹芯结构非线性热传导分析

针对复合材料夹芯结构温度场分布的特点, 提出一种用于复合材料夹芯结构热传导精细分析的有限单元模型。这种单元模型为三维六面体模型, 单元模型厚度方向的插值函数在芯层和面板交界节点处温度值是连续的, 但温度变化率是不连续的, 而芯层内部节点处沿厚度方向温度值和温度变化率都是连续的。在考虑材料热传导参数随温度变化的情况下, 基于这种有限单元模型建立的复合材料夹芯结构瞬态温度场分析有限元方程为非线性方程。在求解此瞬态热传导非线性有限元方程时, 改进了常用的动力学平衡方程的解法, 改进后的动力学平衡方程解法避免了迭代运算, 提高了求解非线性动态平衡方程的效率。数值算例结果显示了该分析模型的有效性和可靠性。 

Nonlinear heat transfer of sandwich composite structure

In terms of the characteristic of temperature field, a precise finite element model (FEM) was established for the sandwich composite structure. The FEM was a 3D hexahedral model. A variety of properties between structure layers was considered in the established FEM. The interpolation function that the value of the function was continuous but the derivative of the function was not continuous at the interface node of layers was chosen to be the field function of the established finite element for the direction of thickness. The corresponding heat transfer FEM equation based on the presented element was also obtained. In terms of the characteristic of the nonlinear ordinary differential heat transfer FEM equation that the thermal property of the material is affected by temperature, the dynamical equation solution was improved. The improved methods will avoid iteration in each time step in the solution process. The numerical example will show the efficiency and reliability of the present method.