Integration Method for Response History Analysis of Single-Degree-of-Freedom Systems with Negative Stiffness

The present article deals with the mathematical investigation of a negative-stiffness ideal system that can be used in seismic isolation civil engineering structures. Negative-stiffness systems structures, because case strong earthquake, they do not easily allow vibrations to develop. These significantly more efficient than usual systems, as drastically reduce vibrational amplitudes well eliminate inertial structure loadings. provides documented answers about effect behavior First, differential equation motion single-degree-of-freedom oscillator (SDoF) is formulated, without classical damping, but negative stiffness. Furthermore, solution given, where it proven this does describe vibration. follows an exponential increase when ground excitation purely sinusoidal. Finally, calculate real response system, suitable modification Newmark iterative numerical method proposed.