Patent ID: 11173691

Abstract:
Methods and apparatus to increase fire resistance and fracture toughness of composite structures are described. An example multi-ply composite structure has at least eleven plies including an innermost ply forming a first external surface of the multi-ply composite structure, and an outermost ply forming a second external surface of the multi-ply composite structure, with the second external surface being located opposite the first external surface. The at least eleven plies further include at least one and no more than three fire-resistant plies positioned between the innermost ply and the outermost ply within either an innermost 33% of the at least eleven plies or an outermost 33% of the at least eleven plies. Respective ones of the fire-resistant plies include an epoxy-based resin and a first additive mixed into the epoxy-based resin. The first additive increases a flammability resistance of the multi-ply composite structure.