Damage Prediction of Integrated Composite T-Joint with Fixed Support Subjected to Low-Velocity Impact: An Experimental and Numerical Study

A finite element model was established based on Hashin failure criteria and the progressive damage theory to predict the damage of integrated composite T-joint structures with fixed support subjected to low-velocity impact. The cohesive zone model was employed to simulate the delamination behaviors of adhesive in the finite element model. The fiber damage and matrix damage of each ply can be provided by the finite element model in details. The damage behaviors of composite T-joint structure subjected to different impact energies were compared using the finite element model. The numerical results showed that the impact caused an elliptical projected area with its major axis along the surface fiber direction. Besides, the in-plane damage dimension is proportional to the impact energy. It is obviously noted that the damage of the first ply is the most serious owing to the delamination between soleplate and fillet caused by the stretching of the L-ribs. A low-velocity impact experiment of composite T-joint was also conducted and the damage dimension was determined by the ultrasonic C-scan. Results showed that the shape and size of our experimental damage agreed well with the simulation results. Our finite element model can be used to effectively analyze the damage behaviors of the integrated composite T-joint subjected to low-velocity impact.