扭转载荷下环形缺口圆轴的统一模型及断裂准则

Unified model and fracture criterion of annularly notched shaft subjected to torsional load

对于具有环形缺口的圆轴,以缺口半径ρ、缺口深度h和缺口张开角α以及圆轴几何尺寸a/b为描述参量,建立各种缺口的统一模型.给出扭转载荷下环形缺口的应力集中系数和环形裂纹的应力强度因子.用有限元计算得到缺口张开角α对无量纲因子fa(a/b)的影响,建立以fa(a/b)为依据的安全设计、断裂设计准则.结果表明:缺口半径、缺口深度和缺口张开角对无量纲因子fα(a/b)均有一定影响.

Taking notch tip radius p, depth h, opening angle a, and geometric size a/b of an annularly notched shaft as descriptive parameters, a unified model for all forms of notches was set up. The stress concentration factor and stress intensity factor of annularly notched shaft subjected to torsional load were given. The effect of opening angle a on dimensionless intensity factor, fa （a/b） was obtained by using finite element method. The criteria for safety design and fracture design were established on the basis of fa（a/b）. The result showed that all of the opening angle a, notch radius, and notch depth had a certain influence on the dimensionless factor fa （a/b）.