Shape optimization of joining interface profile for maximizing the tensile load carrying capacity of scarf jointed plates of dissimilar materials

Abstract

The shape optimization of joining interface profile is performed for maximizing the tensile load carrying capacity of scarf jointed plates of dissimilar materials. On the basis of the two-dimensional theory of elasticity, we first examine the stress singularity at an edge of joining interface, and elucidate the disappearance of stress singularity for the ratio of shear moduli of dissimilar materials G₁/G₂ and the intersection angle θ^* between the joining interface and the surface of scarf jointed plate. The region of the disappearance of stress singularity is represented in the θ^*−G₁/G₂ diagram. After the examination, we formulate the shape optimization problem of joining interface profile for maximizing the tensile load carrying capacity of scarf jointed plate under the constraint that the stress singularities disappear at the both edges of jointed interface. The two-dimensional boundary element method with quadratic isoparametric boundary elements of joining interface is used for the stress analysis of scarf jointed plates of dissimilar materials, and the optimum shapes of jointed interface profile are determined by solving the optimization problem using the method of feasible directions. As the results, it is found that the enhancement of the tensile load carrying capacity of scarf jointed plates of dissimilar materials can be achieved by slight modification of planar joining interface profile.