抄録
This paper studies a method for evaluating the stress triaxiality and the fracture strains accurately considering the deformation of thin steel plates which are used for an automobile body frame. Three-dimensional displacements and surface strains of thin steel plates are measured using a stereovision. In particular, to measure the deformation of the board thickness of the steel plates, the measurement is performed from the both sides of the steel plate. Based on strain incremental theory, the stress triaxiality is evaluated from the measured strains considering the variation of the thickness of the steel plates. The effectiveness of the proposed procedure is validated by applying to the evaluation of the stress triaxiality of high strength steel plates. Results show that the stress triaxiality and the fracture strains can be evaluated accurately by the proposed method.
