劲条止裂性能的分析方法

对于含裂壁板，采用劲条进行局部加强，可以阻止或延缓裂纹的扩展。本文对此作了理论分析，提出了劲条跨过裂纹对称加强时，裂纹尖端、劲条与壁板胶结界点以及劲条端点处应力强度因子的计算方法。在此基础上，通过数值计算，考察了劲条的刚度参数以及问题的一些几何特征参数对劲条止裂性能的影响规律。结果表明，本文方法对于劲条止裂性能的分析是有效的，它不仅能够准确地处理其中的应力奇异性问题，而且运算快速省时，便于进行优化设计。

An Analysis Method of the Efficiency for a Finite Stringer to Retard Crack Growth

Bonding a finite stringer over a local cracked region in a plate has been testified to be able to retard efficiently the crack growth. It is investigated theoretically in this paper. For the case that a finite stringer is symmetrically bonded over a crack in a plate,an analysis method for calculating the stress intensity factors at the crack tips,the fronts of the internal adhesively bonding region and the ends of the stringer is developed,which can be used to evaluate the efficiency of the stringer for retarding the crack growth. Based onthis,a large numerical results are worked out to show the effects of a stiffness parameter of the stringer and some geometrical characteristic parameters of the problem on the efficiency of the stringer for retarding crack growth. From these numerical calculations it can be seen that the analysis method in this paper is effective and rapid and hence can be conveniently used in the optimum design of the damage tolerance for aerospace structures.