Nonlinear equivalent modeling method for clamp based on test data

In order to calculate the vibration response of clamp piping system quickly and accurately, a nonlinear equivalent modeling method for clamp was presented based on test data. The finite element model of simple straight pipe system was modified by the test data of modal test to identify the liner stiffness and damping parameters of clamp. The constant force test was carried out for the simple straight pipe system under different excitation levels. The constant force frequency response function was transformed into constant displacement and constant velocity frequency response function by spline interpolation polynomial method, and the nonlinear equivalent stiffness and damping of clamp were further identified. Finally, the equivalent dynamic model of clamp considering nonlinearity was established. The results showed the maximum error between the predicted frequency response functions and the experimental frequency response functions was only -6.9%. It proves that the equivalent dynamic model of clamp can effectively reflect the actual stiffness and damping characteristics of clamp, and has important guiding significance in vibration response analysis of clamp piping system.