【摘要】 对表面裂纹线弹簧模型进行改进,初步解决未改进的线弹簧模型在远离裂纹最深处(即靠近自由表面处)误差较大的问题。着重对线弹簧本构关系(即模型的内部解)作改进。在内埋椭圆裂纹应力强度因子解的基础上,籍助应变能方向导数的关系将它转变为二维穿透裂纹,引入修正系数得到改进的边裂纹板条解,即改进的线弹簧本构关系(改进的内部解)。外部解采用Reissner板理论。用改进的模型计算表面裂纹前缘法向应力强度因子,结果与Newman有限元解进行较系统的比较,表明改进的模型能在较大范围内更好地与Newman解相符。更多还原

【Abstract】 A modified line spring model is proposed. The problem that there is much error in the crack part near free surface of the plate or shell by un-modified model is resolved by the modified model.The modification is mainly in the internal solution of the model(the constitutive relation of the spring). The stress intensity factor (SIF)of embedded elliptical crack in infinite body is transferred to the SIF of through crack in infinite plate by strain direction derivate. Therefore, a modification coefficient is lead into the internal solution of the model(the solution of edge cracked plate) and the modified model is introduced. The SIF of surface crack is calculated by the modified model. The result is conformity to the Newman solution by finite element method in wide range including the crack part near the free surface of the plate.更多还原