Prediction of the layer longitudinal compression strength

This paper presents a new approach to the prediction of the layer longitudinal compression strength of continuous fibre polymer matrix composites. It is known that failure is caused by fibre microbuckling and that the initial fibre waviness and the matrix non-linear behaviour play a major role. A previous model compared very well with experimental results, but required a relatively complex numerical solution procedure. In the present model, the compression strength is obtained by solving a fourth-order polynomial equation. Although based on several simplifying assumptions, the model is in good agreement with the numerical model predictions and with experimental data. Further model simplifications lead to a closed-form expression that seems to be valid for carbon and boron fibre composites