Damage modelling of repeatedly impacted square fibre-reinforced polymer composite tube

This paper proposed a lifetime prediction model to characterise the damage response of square fibre-reinforced polymer (FRP) composite tubes under repeated axial impact. The model, which is a function of damage parameter D and normalised impact number Nf, used an energy-based approach. Series of impact and quasi-static compressive tests on composite tubes were undertaken to determine the required parametric values and to validate the reliability of the proposed model. Testing was performed by axially impacting 100 mm FRP pultruded tubes to 130 repeated impacts or up to collapse using a drop-mass type impact apparatus. The quasi-static compressive test was conducted using a 2000 kN capacity servo-hydraulic compressive testing machine. Results showed that the impact fatigue curve of the composite tubes follows a power function relationship. The variation of incident energies Ein between the fitting curve and experimental data is less than 3%. A good agreement is observed between the experimental data points and the prediction model.