Electromagnetic Riveting Study

Electromagnetic riveting is a new type of riveting process. In the process, the strain rate of metal material is high and the mode of the deformation of rivet material is different from that of conventional riveting methods. The purpose of the work is to analyze the factors which make effect to the riveting quality, in particular, to analyze the relation between geometrical form of riveting die and the deformation of rivet tail, and provides the theory of optimizing design of riveting die. It is found that the angle of riveting die affects obviously shear stress and shear strain of rivet tail; and decreasing the angle can improve the distribution of the strain, and prevent riveting cracks in rivet tail.The author of this paper uses LS-DYNA program packages to simulate nine kinds of rivet die. And the angle of the die is varied from 15 to 55 degrees. Through the data of numerical simulations, some relations between the angle of the die and the quality of the formed head of rivet, and between the angle of the die and quality of the riveting are found out. And the author also analyzes the mechanisms behind such kinds of relations theoretically.Experiments indicate that the results of the numerical simulation are proper.