Prediction of compressive strength for unidirectional fiber reinforced plastics in considering effect of strain-rate dependency on mechanical properties of constituent materials

This study presents an analytical model to predict compressive strength of unidirectional FRP. Proposed model considers the effect of strain-rate dependency on mechanical properties of constituent materials. The model is based on the elastic foundation model and the microbuckling model of fiber which has initial misalignment in matrix. Compressive deformation of unidirectional FRP is considered by dividing into fiber microbuckling region and plastic kinking region. Additionally, to take into consideration the change in compressive deformation mode accompanying fiber volume fraction or fiber microbuckling, A mode function is introduced. The predictions from the proposed model are compared with experimental results of unidirectional E-glass/Epoxy and T700SC/Epoxy evaluated by using the conventional split Hopkinson pressure bar method. Incorporating strain-rate dependency on compressive modulus of reinforcement calculated from composite mixture law, the predictions are found to be in good agreement with experimental results of strain-rate dependency on compressive strength. Accuracy of the prediction is improved by changing the mode function.