Low velocity impact behaviors and highly residual compressive strength of epoxy foam-filled 3D woven composites

In this work, a new type of epoxy foam-filled 3D woven spacer composites (FF-3DWSCs) was designed and manufactured by self-made 3D loom and foaming technology. The low velocity impact behaviors, residual compressive properties and strengthening mechanisms of epoxy foam were systemically investigated. As the results, the FF-3DWSCs showed higher impact load of 4000-5200 N than that of 3D woven spacer composites (3DWSCs) (2800-4300 N) at the energy from 10 to 40 J. The residual compressive strength of FF-3DWSCs (23.85 MPa) was maintained at about 80% after 30 J energy impact. Due to the good compatibility of the epoxy foam and the epoxy resin and the synergistic effect between the pile yarn and the epoxy foam, the interface between epoxy foam and fiber/epoxy was strong. Therefore, the novel FF-3DWSCs proposed here exhibited excellent impact properties and energy absorption capacity and can be used as a candidate material in the field of high-performance composites.