轴表面半椭圆裂纹应力强度因子的求算

Evaluation for SIF of the Semielliptical Surface Crack of a Axle

评价了将轴表面半椭圆裂纹简化为有限边界平板的单边裂纹问题和半无限体表面穿透直线裂纹问题来处理的局限性．通过三维光弹实验成功地测定了弯扭载荷作用下的轴表面半椭圆裂纹前缘各点的ＳＩＦ（ＫⅠ，ＫⅡ，ＫⅢ），并根据几组光弹数据回归出轴表面对ＳＩＦ的影响修正系数ＭＹ与裂纹相对深度ａ／Ｒ之间的关系曲线．从而对目前尚无理论解的轴表面半椭圆裂纹的ＳＩＦ求解提供了依据，有一定的工程意义．

Evaluats the limitations of which semielliptical surface crack is simplified to unilateral crack of a difinite boundary plane and cross straight-line crack of a semi-infinite body.The SIF(KⅠ,KⅡ,KⅢ )of the semielliptical surface crack are determined at different points along the front of the crack in a model axle subjected to moment and torsional load by means of three-dimensional photoelastic experiment, and the relation carves between the correction coefficent MY of axial surface and the relative crack depth a/R are regressed by the photo-elastical experiment data.The results form a basis of investigating SIF of the semielliptical surface crack,for which there is not any tneoretical solution so far,is significant in engineering.