Simplified Design Procedures for Composite Plates Under Flexural Loading

Abstract

The paper describes simplified procedures for the design analysis of rectangular plates loaded in flexure and compares predicted results with test data on a range of fibre reinforced plastics plates. Design formulae and design charts are given for determining maximum deflections and bending moments in rectangular orthotropic elastic plates under transverse pressure or point loads. The design methods are based on computed solutions to the orthotropic plate equations whose results are presented as simplified design charts appropriate to composite applications and depending mainly on a single stiffness ratio parameter. Design formulae, derived from approximate variational solutions to the orthotropic plate, are shown to be in good agreement with the computed solutions especially for materials with low and moderate stiffness ratios. Flexure tests are reported on a range of reinforced plastics plates with mat, woven, unidirectional or cross ply reinforcement and subjected to centre point transverse loads. Measured deflections are compared with predicted values and the validity of the design procedures is assessed.