压气机轮盘孔边应力的边界元分析

 本文根据压气机轮盘的轴对称问题,取出轮盘包含孔的一个扇形部分,以有限元法计算的结果作为扇形部分的边界条件,采用边界元法计算轮盘孔边的应力。这与直接用有限元法计算结果对比表明,边界元法具有数据准备工作量小、方便,计算点选择灵活,计算精度高等优点,用于计算孔边的应力集中问题是有效的。文中还推导丁常单元的二阶差分逼近式,用以求解边界上的应力。

NUMERICAL ANALYSES OF STRESS NEAR THE HOLE OF COMPRESSOR DISK BY BOUNDARY ELEMENT METHOD

Boundary elemem method (BEM) is used to calculate the stresses near the hole of a compressor disk. Since the disk is axisymme-trical, one sector of the disk with a hole is chosen and the numerical results of FEM are used as the boundary conditions ol the sector. The numerical results of BEM are compared with those of FEM. The result shows that when BEM is applied, the data to be prepared is less but more convenient; the choice of the points to be calculated is more flexible, the numerical precision is better. In order to obtain the stresses on the boundary, the 2nd finite difference approach equation for the constant element is derived as well.