Analysis of the critical state of a discrete-inhomogeneous strip with a tilted contact boundary and an external macrodefect in its more durable part

The article considers the stress state of a joint in the form of an elastic-plastic strip with rectilinear parallel edges under conditions of plane deformation. The strip consists of two parts of different strengths made of homogeneous isotropic materials, separated by a straight line which is forming an arbitrary angle with the edge of the strip. The joint is subjected to tensile stress. In its stronger part, there is a surface macrodefect in the form of an external incision or recess. The purpose of the article is to study the critical state of the joint using various geometrical and mechanical parameters and, on this basis, calculate the critical tensile force. The method is based on the study of characteristic fields (slip lines) in the plastic zone, taking into account the presence of a voltage break in the more durable part. A complete analysis of variations of the patterns of characteristic fields leading to different stress diagrams over the net cross section is given, depending on the relative position of the defect and the contact boundary, the size of the defect, the angle of inclination of the contact boundary, and the coefficient of mechanical heterogeneity of the joint. An algorithm has been developed to calculate the critical tensile force in the general case. The average critical stresses in the most characteristic cases have been calculated.