An experimental, numerical and analytical study of local buckling in perforated plates

• GMNIA models are successfully created with DIC-found imperfection data • FE and experimental results exhibit good agreement until ultimate collapse • Mode prediction for a regular hole array extends to irregular and staggered arrays • Plates with tall staggered perforations exhibit Lateral Perforation Buckling This paper presents the results of a series of uniform buckling compression tests conducted on simply supported perforated thin aluminium plates. Seventeen perforation designs are examined including regular, irregular, staggered, and patterned arrangements. Digital image correlation (DIC) is used to completely inform the size and shape of the initial geometric imperfection in all tested plates. Using the stress-strain curve obtained from tensile coupon tests, a geometrically and materially nonlinear (GMNIA) finite element (FE) model is developed to assess the compressive behaviour of all perforated plates. The numerical predictions are then compared against the corresponding experimental force-displacement results. The relationship between perforation characteristics and elastic buckling behaviour is also discussed. A linear perturbation procedure is then undertaken to compare the elastic buckling capacity of perforated plates to recent analytical predictions, which perform with high accuracy. Recommendations are made to improve the predictions in cases where the modeshape is incorrectly determined. Overall, this research makes a significant contribution to the identification of local buckling modes for perforated plates using analytical methods in absence of FE simulations.