Abstract
The Idealised Structural Unit Method (ISUM) is known as a simple but efficient method to simulate buckling/plastic collapse behaviour of structural systems. To perform collapse analysis of structures composed of girder webs and plate flanges such as a ship's double bottom structure, it is necessary to develop a new ISUM element which can simulate buckling collapse behaviour of a girder web with a cutout. In the present paper, a series of collapse analyses with conventional FEM is firstly performed changing the size, the shape and the location of a cutout. On the basis of the results of FEM analyses, a new ISUM element which can simulate the buckling collapse behaviours of a rectangular plate with a cutout subjected to thrust in the transverse direction is developed. Through comparison of the calculated results with those by FEM analysis, the applicability and the accuracy of the new ISUM plate element are demonstrated.