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

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, w here the principal stresses are equal, are automatically extracted on an im age with the directions of principal stresses obtained from the computerize d photoelastic experiment. The finite element method is then used fur analy sing the models with holes differing in size at an isotropic point extracte d experimentally. Finally, the hole size is determined, comparing with stre ss distributions around those holes. The present method is applied to a T-s haped plate subjected to a compressive load. As a result, the stresses in m odels with holes at locations different from the isotropic point are higher than those with the same-size hole at the isotropic point. Therefore the p roposed method is effective for optimally designing structural members with holes.