IMPACT RESISTANCE OF GRADIENT NEGATIVE STIFFNESS CELLULAR STRUCTURE

摘要

A negative stiffness cellular structure is designed and modelled by periodically arranging negative stiffness cells in this paper, each of which comprises two sets of central-clamped double curved beams. Geometrical parameters of the curved beams vary from row to row, resulting in gradient distribution of force thresholds along the height and a cascading series of reacts to different shock intensity. The static behavior, which describes the relationship between the compression force and displacement, has been discussed via numerical analysis and compared to analytical results. Different dynamic load cases were conducted to investigate the impact resistance of the structure. With different numbers of beams buckling at various impact load amplitudes, the results show that the structure is effective to reduce shock response and to protect the objects from sharply damage. Almost 80-90% of the input energy can be absorbed without any loss of function.