基于结点位移插值的约束子结构界面自由度缩减方法

DEGREES OF FREEDOM REDUCTION TECHNIQUE FOR INTERFACE OF CONSTRAINED SUBSTRUCTURE BASED ON NODE DISPLACEMENT INTERPOLATION

基于结点位移插值原理,建立了约束模态子结构界面自由度的缩减方法,形成了约束子结构模态综合法的二次坐标变换矩阵。通过第二次坐标变换可有效地缩减计算系统的广义自由度,提高计算效率。算例表明,这种缩减方法是合理有效的。该文还讨论了插值基点的选择方式对计算精度的影响,计算结果表明,当选择的插值基点在界面上均匀分布时,计算精度最好。最后,对比了插值域的形状对计算精度的影响,计算结果表明,矩形插值域的计算精度要好于三角形插值域。

Based on a node displacement interpolation formulation, the interface degrees of freedom reduction technique for a constrained substructure was developed in this paper, and the second transformation matrix was constructed for a constrain substructure modal synthesis method. The generalized degrees of freedom of the system were reduced effectively by using the second transformation matrix, thusly the calculating efficiency can be improved. The numerical examples demonstrate that the interface degrees of freedom reduction technique suggested in the paper is reasonable and effective. The influence on the calculation accuracy of the choice of interpolation nodes was discussed, and the numerical results show that the calculation accuracy is the highest if the interpolation nodes uniformly distribute on the interface. At last, the influence on the calculation accuracy of shape of interpolation areas was also studied, and the results indicate that calculation accuracy is higher when using the interpolation areas in the shape of rectangular than the case in the shape of triangle.