Abstract — The stability of perforated plates with an in-plane pre-load at central circular opening were studied. Parametric investigations were conducted by varying the diameter of opening and the magnitude of in-plane force. The effect of aspect ratio (edge-length to thickness) was examined. Three sets of numerical models were prepared. First, the plate structures without any openings (pristine) were simulated for critical buckling loads. Results were verified with theoretical closed form solutions. Second, circular openings were introduced on the same models and simulations were repeated. Finally, all models were simulated with in-plane pre-loads at cutouts. Plots representing Eigen values versus plate slenderness ratio were presented. Critical stresses for stability were calculated in relation to applied in-plane load at cutouts. Finally, a design equation for critical stress values was developed for a perforated plate. Keywords—Buckling, Perforated plate, ABAQUS, Simply supported, 316L. Notation: FE —Finite Element LPS — Local Positioning System SEL — Shell Edge Load   — Critical stress for instability    — Critical stress for instability with pre-load   — Normal stress parallel to  axis   — Distributed load parallel to  axis  — Elastic Modulus  — Poisson’s ratio  — Thickness of plate  — Plate buckling coefficient  — Plate buckling coefficient for a perforated plate  — Width of plate  — Length of plate  — Aspect ratio of plate (  )  — Slenderness ratio of plate (  )  — Number of Half-waves   — Critical unit compressive force  — Diameter of circular opening   — Total force applied   — Applied Shell Edge Load  — Multiplication factor Sathish Nammi, Jean-Luc Mauricette and Hassan Shirvani are with Anglia Ruskin University a , Chelmsford, CM1 1SQ, UK (*Corresponding Author Phone: 0845-196-3900; sathish.nammi@anglia.ac.uk ). Imran Patel is with University of Hertfordshire b , Hatfield, AL10 9AB. I. INTRODUCTION The stability of structures is an important area in civil, mechanical, marine, aerospace and many other fields of engineering. Therefore structural stability problems can manifest in a myriad of ways. The field of solid mechanics examines many classic problems on stability criterion, and there is an extensive literature available on fundamental problems in applied mechanics [1], [2]. However, solutions to problems with varying boundary conditions and various possibilities of loads is a challenge, where there are many gaps in knowledge. There are many facets to engineering problems that require further study; one such area is in multi-loading scenerios involving perforated plates. In this paper, a plate without any cutout and with a cutout will be referred to as pristine and perforated. Most published information is largely on pristine plates, whereas perforated plates are still an area requiring further research, especially under complex loading scenerios. Most literature on perforated plates pertain to loads subjected to pure uniaxial, biaxial or shear loading ([3]-[4]). However, problems involving how pre-loads on a centrally located opening affect stability have not been given thorough attention which the current investigations focus upon. The critical load under edge compression is computed for specific dimensions of a perforated plate. Investigations are limited to elastic buckling cases with intention for future research to extend to inelastic problems, with critical instability stresses examined for various slenderness ratios of plates. II. PROBLEM DESCRIPTION AND JUSTIFICATION OF RESEARCH A schematic of a perforated rectangular perforated plate lateral and longitudinal dimensions of 203.2 × 254 2 and a circular cutout at its centre is shown in Fig 1. Its critical buckling stress diminishes when this plate is subjected to an inplane distributed pre-load on the circular opening. The aim is to develop an equation for critical buckling stress with a known pre-load at its circular cutout. The plate shown in Fig 2 is of a blast resistant enclosure with its front face reinforced with steel and Al foam designed to withstand low yield frontal blast loading. Such reinforcements can be extended to one or more faces depending on the requirements. Stability of Perforated Plates with an In-plane Pre-load on Central Cutout Sathish Nammi a *, Jean-Luc Mauricette a , Imran Patel b and Hassan Shirvani a Proceedings of the World Congress on Engineering 2016 Vol II WCE 2016, June 29 - July 1, 2016, London, U.K. ISBN: 978-988-14048-0-0 ISSN: 2078-0958 (Print); ISSN: 2078-0966 (Online) WCE 2016