常见薄壁拉伸构件带中心裂纹时的应力强度因子公式

A Series of Simple SIF Formulations of Model I Center Crack in Tensile Thin-walled Member

首先根据无限大中心裂纹板在I型荷载作用下应力分布的近场奇异解,构建薄壁杆件在均匀拉伸时沿裂纹所在截面的正应力的分布模型;然后利用平衡条件确定无量纲应力强度因子;从而建立了一种求解含中心裂纹薄壁杆件应力强度因子的面场分析近似方法。与现有的数值结果比较表明,该方法不仅简单实用,而且结果可靠。文中给出的几种常见薄壁杆件含I型中心裂纹时的无量纲应力强度因子的近似简单解析表达式,既适用于焊接组合薄壁杆件,也适用于冷弯薄壁杆件。

Based on the analytical solution of stress field around the center crack in an infinite sheet,the normal stress distribution model was established on the cracked cross section for tensile thin-walled member. The dimensionless stress intensity factor Y(ξ) included in the distribution model was determined by use of the equilibrium condition of the isolated semi cracked sheet. The simple formulations of dimensionless stress intensity factor (SIF) Y(ξ) can be obtained by means of above approximate method. By contrast with the only one numerical results of reference [1,5] the simple formulation in this paper is reliable to structure engineering and can be applied to both welded and cold-formed thin-walled members.