一组适合于带纵向裂纹柱体圣维南扭转的等参数元素

本文给出一组新的适合于带纵向裂纹柱体圣维南扭转的等参数元素,它们分别是八结点等参数元素、在裂纹尖端具有r-1/2奇异性的“1/4”八结点等参数元素及八结点过渡元素.利用这些元素,对含有径向纵裂纹的圆柱体进行了圣维南扭转计算.计算结果表明,本文给出的等参数元素有较高的精度、较好的收敛性及快的收敛速度,同时还具有程序简单、省机时等优点,所以特别适合于实际的工程计算.

A Group of Isoparametric Elements Suitable for St. Venant's Torsion of a Bar with Cracks

In this paper, we shall give a group of new isoparametric elements suitable for St. Venant 's torsion of a bar with vertical cracks. These elements are eightpoint isoparametric element, quarter eight-point isoparametric element and eightpoint isoparametric transition element. Among these elements, the second and the third elements possess the singularity of order r-1/2 at crack tip. Using these elements, we have completed the calculation of St. Wenant 's torsion for a cylinder with a radial Yertical crack. The calculated results show that the isoparametric elements given by this paper have ideal accuracy, good convergence, high speed of convergence, low freedom and little computational time, and so they can be widely applied to practice.