Energy absorption characteristics of STF impregnated Kevlar fabric coating GFRP composite structure by projectile high-velocity impact

The new STF impregnated Kevlar fabric coated GFRP (glass fiber reinforced polymer) composite structure obtained by combining STF（shear thickening fluid） impregnated Kevlar fabric and GFRP can obtain strong energy absorption capacity with light weight compared with two separate structures, so it has strong impact resistance. In this paper, the experiments of STF impregnated Kevlar fabric, GFRP laminated plate and STF impregnated Kevlar fabric coating GFRP laminated structure were carried out, respectively. Based on reliable numerical simulation, the macroscopic damage and energy absorption characteristics of the same material in STF impregnated Kevlar fabric, GFRP laminated plate and STF impregnated Kevlar fabric coating GFRP laminated structure were analyzed. The results show that the GFRP laminate and the rear Kevlar fabric in the STF-impregnated Kevlar fabric coating GFRP laminate structure show a larger damage area than that of GFRP laminate and STF impregnated Kevlar fabric alone, and a larger deflection is generated during the process of impact. The increase of the number of layers of Kevlar fabric in the front and back of the laminate and the increase of the thickness of the laminate make the Kevlar fabric absorb more energy. If the energy absorption capacity of GFRP laminates is increased, the number of layers of the front Kevlar fabric can be reduced, the thickness of the laminates can be increased, and materials with greater strength can be added to the front ply of the laminates. However, increasing the thickness of GFRP laminates will reduce the lightweight requirements of laminated structures.