Method for nonlinear parameter identification of a continuum structure with clearance

Clearance is unavoidable in the mechanical system. However, contact nonlinearity caused by the clearance can significantly affect the system, which leads to the result that the dynamic response deviates from the ideal state and the performance and service life of the mechanical systems will be reduced. If the parameter of the clearance nonlinearity can be identified by taking advantage of dynamic characteristics, the clearance of mechanical systems can be controlled in a reasonable range. Based on the continuum structure with clearance, a method of combining the modified restoring force surface (RFS) and the conditioned reverse path (CRP) is proposed to identify the nonlinear parameters of the system. The space-reduced-order model can be simplified from the differential equation derived by the Hamilton principle. Based on the dynamic information, the clearance value of the continuum system can be identified by the modified RFS method. And then, the contact stiffness can be identified by the CRP method. The entire identification process is simulated in the Matlab software, and the parameter identification experiments are conducted on the designed testbed with adjustable clearance. The results show that the precision of the identification method is high, and the effectiveness of the proposed method is verified.