Development of a negative stiffness friction damping device with an amplification mechanism

•A novel negative stiffness friction damping device (NSFDD) was proposed.•Large force capacity of NSFDD was realized by two-consecutive lever and gas spring.•A mechanical model was proposed to represent force–displacement relationship of NSFDD.•Performance of NSFDD was examined by experimental tests and finite element analyses.•The NSFDD exhibited obvious negative stiffness and stable energy dissipation.