Ultimate strength of square plate with rectangular opening under axial compression

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

[1]  M. D. Motok,et al.  Stress concentration on the contour of a plate opening of an arbitrary corner radius of curvature , 1997 .

[2]  Jeom Kee Paik,et al.  Advanced ultimate strength formulations for ship plating under combined biaxial compression/tension, edge shear, and lateral pressure loads , 2001 .

[3]  N. E. Shanmugam,et al.  Design formula for axially compressed perforated plates , 1999 .

[5]  R. Sundaravadivelu,et al.  Stability of initially stressed square plates with square openings , 1992 .

[6]  C. Guedes Soares,et al.  Design equation for ship plate elements under uniaxial compression , 1992 .

[7]  C. Guedes Soares.  A CODE REQUIREMENT FOR THE COMPRESSIVE STRENGTH OF PLATE ELEMENTS , 1988 .

[8]  T. M. Roberts,et al.  Strength of perforated plates subjected to in-plane loading , 1984 .

[9]  R. Narayanan,et al.  Ultimate capacity of uniaxially compressed perforated plates , 1984 .

[10]  C. D. Bradfield.  Tests on plates loaded in in-plane compression , 1980 .

[11]  Analysis of plated structures with rectangular cutouts and internal supports using the spline finite strip method , 1994 .

[12]  S. L. Chan,et al.  Ultimate capacity of plates containing holes under linearly varying edge displacements , 1985 .

[13]  M. Toulios,et al.  The effect of aspect ratio on the elastoplastic response of stiffened plates loaded in uniaxial edge compression , 2002 .

[14]  N. E. Shanmugam.  Openings in Thin-Walled steel structures , 1997 .

[15]  A. Nazmy,et al.  Elasto-plastic buckling of perforated plates under uniaxial compression , 2004 .