On the prediction of cure-process shape deviations in fibre metal laminates

An investigation of the fabrication-induced distortions in fibre metal laminates is presented using finite-element modelling and experiments. Cooling down is considered as the main source of distortion. Four fibre metal laminate panels are manufactured and their curvature is measured using digital image correlation and linear variable differential transformer. The curvatures are the response of the non-symmetric lay-up to different parameters like stacking order and number of composite or metal layers. Acceptable agreement between model and experiment in predicting the geometry shows that the laminate shape can be predicted with reliability. A large displacement model should be used for large shape deviations in laminates with high level of non-symmetry. Fibre metal laminates may have single or multi-stable configurations after removal from the layup tool. This phenomenon is analysed and parameters and modelling considerations are investigated to obtain a method to predict the final configuration. Further modelling and experimentation are needed to improve the quality of the predictions with increasing complexity of the component.