Impact response of bio-inspired laminated composite plates: A numerical simulation model using 2D shell element

In this study, a numerical simulation model is developed to investigate the load response of the low velocity impact of unidirectional carbon fiber-reinforced polymer (CFRP) plates using the commercial explicit finite element code LS-DYNA. The main objective is to develop an accurate computational model capable of simulating the impact procedure on the composite structures. In the first part, the numerical simulation model is developed based on published experimental work for 300 x 150 x 2.7 mm CFRP plate consisting of 24-ply. The CFRP plate is impacted by a hemispherical steel impactor of 25.4 mm diameter and 6.5 m/s speed to generate 40 J of impact energy. A 2D modeling approach with a single shell element is adopted. The plies thickness and fiber-orientations are defined using PART_COMPOSITE. The linear-elastic composite material model MAT54 based on the failure criteria is used to define the unidirectional composite material, while MAT20 is used to define the impactor material as a rigid body. Control parameters in MAT54 have been successfully calibrated to match the experimental results. The numerical simulation results show a strong agreement with the experimental results in terms of absorbed energy, impact force, and deflection plots. The absorbed energy value from the numerical simulation is very close to the experimental result, with a difference of 2.86%. Only 0.85% of the impact force value is different between the numerical simulation and the experimental result. The maximum deflection obtained is identical with the experimental result. In the second part, the developed model is used to study the impact response and resistance of different layup configurations [i.e., Unidirectional (UD), Cross-Ply (CP), Quasi-Isotropic (QI), Linear bio-inspired Helicoidal (LH), and nonlinear bio-inspired Fibonacci-Helicoidal (FH)]. Although the QI and LH layup configurations do not show the lowest value for the impact force neither the absorbed energy, they produced the lowest deflection values for the current impact condition. It can be concluded from this study that the following numerical simulation model can be effectively utilized for the purpose of designing and analyzing innovative bio-inspired composite structures in various configurations under different impact scenarios to study the load response.