Maximum Strength Analysis of Postbuckled Rectangular Plates

An analysis of long simply-supported rectangular plates with straight unloaded edges uniformly shortened beyond the elastic instability points into the plastic range was undertaken. The inclusion of wavelength effects is shown to be a significant factor in establishing maximum strength criteria for postbuckled plates. The present results are shown to be in excellent agreement with experiment and serve to explain the reason for the absence of clearly-defined maximum load criteria for postbuckled square plates. In addition, the analysis results offer a plausible explanation for the increased maximum strength performance obtained with several tests on beryllium plates considered to be simply-supported, when compared with an essentially material-independent maximum strength criterion established for plates constructed of materials which possess relatively high biaxial ductility. (Author).