The Strength of Dissimilar Fractal Joints

Abstract

In this investigation, the influences of fractal geometry and material properties on the strength of dissimilar joints were studied. The fractal geometry explored was an iterative Koch curve. The interfacial layer joining two different materials was designed to be a Koch layer with three different numbers of iteration. The mechanical behaviors of the fractal dissimilar joints under both normal tensile traction and shear traction were simulated via finite element (FE) method. In the three-phase FE models, isotropic elasto-perfect-plastic material models with different stiffness and yielding strength were used for all three phases. By varying the stiffness and strength ratio of the Koch layer and the dissimilar materials, fractal dissimilar joints with both perfect bonding and imperfect bonding were simulated and compared. It was found that the fractal geometry plays a very important role in enhancing both the tensile and shearing strength of dissimilar joints, especially for the cases with imperfect bonding.