型材筋条裂纹的应力强度因子的工程计算

A Better Model for the Engineering Calculation of Stress Intensity Factor for Stiffener Containing Crack

计算含裂纹筋条的应力强度因子。通过一定假设及工程简化 ,考虑型材上其余部分的弯曲刚度对含裂纹板条的作用 ,形成了改进的准三维模型 ,并编制出相应的有限元分析程序。在假设基础上建立了裂尖正好位于拐点处的有限元模型。通过角材筋条的实例计算 ,获得了裂纹延伸并经过拐点的应力强度因子的连续曲线。本文所提出的方法适用于更复杂的型材筋条的分析。

Multi-site damage in aircraft stiffened panels has brought about a closer examination of crack-tip stress intensity factors of crack-containing stiffeners. Existing models for calculating such stress intensity factors appear to require more or less adjustments to bring calculated results in line with reality. We modified the partial compatibility model in Refs.[1] and [2] to make it better. As 2D finite element method is convenient for engineering purposes, we considered a stiffener with zigzag section as several connected strips in the same plane. During discretization, we, like Refs.[1] and [2], made adjacent strips compatible in longitudinal direction along their intersection line. Unlike Refs.[1] and [2], we, with some assumptions, represented by an appending beam the effect of transverse bending deflection of all the other strips on the crack-containing strip. We made calculations for an angle section stiffener as a numerical example.