Patent ID: 6574570
Filing Date: 2003-06-03
Classification: G01M

Abstract:
A method for analyzing nonlinear restoring force characteristic with hysteresis of a machine structure system, comprising:performing approximate mode analysis by representing said nonlinear restoring force characteristic with hysteresis by an equivalent linear characteristic, when a nonlinear restoring force characteristic of a machine structure system, having force-displacement hysteresis, is analyzed, wherein the representation of the nonlinear restoring force characteristic by said equivalent linear characteristic includes the steps of: first obtaining a basic nonlinear restoring force characteristic experimentally or simulatively based on a relation between an input and an output of an actual system; then obtaining a transmission characteristic, equivalent rigidity, and equivalent viscous damping by numerical analysis based on a relation between a sine wave input with respect to said basic nonlinear restoring force characteristic and a fundamental wave frequency component of an output of the sine wave input distorted after passing through said basic nonlinear restoring force characteristic; and obtaining a frequency response characteristic of the entire machine structure system by uniting said transmission characteristic, said equivalent rigidity and said equivalent viscous damping with a multi-degree-of-freedom equation of motion.