Application of isotropic points extracted using computerized photoelastic experiment to design structural members

Abstract

This study investigates a method for optimally designing structural members with holes, which are made to decrease the weight of and to pass pipes and wires through these members. In this method, first the isotropic points, where the principal stresses are equal, are automatically extracted on an image with the directions of principal stresses obtained from the computerized photoelastic experiment. The finite element method is then used for analysing the models with holes differing in size at an isotropic point extracted experimentally. Finally, the hole size is determined, comparing with stress distributions around those holes. The present method is applied to a T-shaped plate subjected to a compressive load. As a result, the stresses in models with holes at locations different from the isotropic point are higher than those with the same-size hole at the isotropic point. Therefore the proposed method is effective for optimally designing structural members with holes.