Ultimate strength of square plate with rectangular opening under axial compression

Abstract

Unstiffened plates are integral part of ship structures, offshore oil platforms, lock gates and floating docks. Openings are provided in these plates for access and maintenance. Provision of opening influences the ultimate strength of plate elements. In this paper the effect of increase in the size of rectangular opening along the loading direction on the ultimate strength is determined using nonlinear finite element analysis. A general purpose finite element software ANSYS is used for carrying out the study. The software is validated for the ultimate strength of unstiffened plate under axial compression. A parametric study is done for different plate slenderness ratios and by varying the area ratio of opening to plate to determine the effect of ultimate strength on the size of rectangular opening. It is found that increase in area ratio along the loading direction decreases the ultimate strength. The variation in ultimate strength varies linearly for plate slenderness ratio less than 2.23 and varies nonlinearly for plate slenderness ratio beyond 2.23 for area ratio ranging between 0.02 - 0.18. Based on nonlinear regression analysis, a design equation is proposed for square plate with rectangular opening under axial compression.

Keywords: Unstiffened Plate, Ultimate Strength, Rectangular Opening, Axial Compression, Design Equation   

DOI: 10.3329/jname.v4i1.913

Journal of Naval Architecture and Marine Engineering 4(2007) 15-26