Abstract
Abstract
The bumpy-ridge structure applied in the field of heavy equipment is analysed based on fracture mechanics and contact theory. At the same time, the elastic—plastic contact of the ridges is simulated using the finite element method. Having been researched, the separated bumpy-ridge structure can be seen as a special integral structure that has a through crack. It was also found that, as long as there are adequate normal forces and treated contact surfaces, this kind of separated structure has the ability to resist detachment and parallel slide. The height of the notch and radius of the contact zone are the foremost indexes affecting the application of the bumpy-ridge technique, and these parameters are influenced by several factors, such as the shape of the ridges, the curvature of the contact point, the distance between neighbouring ridges, etc. The elastic contact of the ridge can be solved completely by the use of theoretical calculation and graphical method. Through comparison with the elastic contact, some principles of the elastic—plastic contact can be obtained with a finite element analysis method. A bumpy-ridge structure has been successfully applied to a 350 MN die forging press and a 360 MN extrusion press in China.