Modeling the damped dynamic behavior of a flexible pendulum

Abstract

The focus of this work is on the computational modeling of a pendulum made of a hyperelastic material and the corresponding experimental validation with the aim of contributing to the study of a material commonly used in seismic absorber devices. From the proposed dynamics experiment, the motion of the pendulum is recorded using a high-speed camera. The evolution of the pendulum’s positions is recovered using a capturing motion technique by tracking markers. The simulation of the problem is developed in the framework of a parallel multi-physics code. Particular emphasis is placed on the analysis of the Newmark integration scheme and the use of Rayleigh damping model. In particular, the time step size effect is analyzed. A strong time step size dependency is obtained for dissipative time integration schemes, while the Rayleigh damping formulation without time integration dissipation shows time step–independent results when convergence is achieved.

Experimental evaluation of damping models for a nonlinear pendulum system

“…Yuan [14] pointed out the limitation of the traditional viscous damping model and proposed a three-parameter damping model whose parameters were obtained experimentally to numerically analyse a four-bar elastic linkage mechanism. Ortega et al [17] indicated that with appropriate parameters, the Rayleigh damping model, which is a type of viscous damping model, in combination with Newmark numerical method can well capture the free vibration of a deformable physical pendulum. Salamon et al [10] investigated the capability of three viscous damping models, namely linear viscous damping model, squared velocity proportional damping model, and velocity and acceleration dependent damping model, in predicting the free vibration of physical pendulum systems.…”