Topological metamaterial plates: Numerical investigation, experimental validation and applications

•The concept of topological insulator is introduced into plates in civil engineering.•Topological and conventional interface states of flexural waves are obtained.•The influence of key parameters on interface states is comprehensively discussed.•Interface states show robustness against defects and material damping.•3D-printed topological metamaterial plates are fabricated and tested.•The feasibility of topological metamaterial plates to vibration mitigation is verified.