Abstract
The advantages of advanced composites materials in the field of structures have been known for many years. Theories for bending of multi-layer plates have been developed to predict the stresses that occur when these structures are subjected to transverse loads. It has been noted by several researchers that when laminated structures are loaded by transverse forces, interlaminar shear stresses are generated. The effects of these shear stresses can have a substantial effect upon the stress distribution within a laminated plate or beam. Little effort has been made to produce a simple elastic solution which includes the effects of the interlaminar shear stress. Another area that has been ignored by researchers has been the problem of the diffusion of contact stresses caused by rollers on laminated beams. No-one has investigated this problem to see if the theory produced by Hertz is still applicable. A simple elastic solution for the bending of shear stresses in a five layered laminated beam has been formulated. The theory includes the effects of the interlaminar shear stress. A two-dimensional photo-elastic model has been tested to provide experimental verification of this analysis. This simple elastic theory has then been developed further to predict the bending and shear stresses in a laminated beam composed of a large number of layers. The theory has also allowed for the laminae having different material properties. In order to investigate the effect of a body contacting with a laminated beam, a new theory is developed in which the effect of a distributed load over part of the span is accounted for. The results of this theory are compared to those for the single point level. An experimental program has been carried out on a two-dimensional photoelastic model representing a roller pressed against a laminated beam. The results of this work have been compared to traditional Hertzian theory.