Session: 30-05 Modeling, algorithms and computational techniques II

Paper Number: 82779

82779 - On the Dynamic Response of a Two-Degree-of-Freedom System With Dry Friction and Elastic Stop 

The contact interface is one of the important components of structural systems, introducing friction and non-smooth constraints, which will cause the nonlinear dynamic behavior. This survey provides an insight into the dynamic response of a simplified model with two moving parts in detail, which can be applied to analyze the dynamic behavior of the pedestal looseness, fit clearance, and support with elastic stop, etc. First, a two-degree-of-freedom system is established, and the nonlinear force caused by friction and elastic stop is introduced between the two moving parts. Dimensionless governing equations is derived, and the harmonic balance method and shooting method are used to obtain the periodic solution, and Floquet theory and Poincaré mapping are applied to analyze the stability. Considering friction merely, the amplitude-frequency curves obtained by the two methods are compared, and the accuracy of the harmonic balance method is verified by the numerical integration method. Then, the features of energy dissipation versus excitation frequency are present, and influences of friction force amplitudes on the dynamic response are studied. Considering friction and elastic stop, the periodic solution is unstable in some excitation frequency ranges, and Hopf bifurcations exist correspondingly, indicating quasi-periodic motion occurs. The frequency domain of periodic motion contains sub-harmonic components merely, while the frequency domain of quasi-periodic motion is composed of combined frequencies. Since Hopf bifurcation indicates a new periodic solution whose frequency is incommensurable with the original one comes up, a formula for the explain of combined frequencies is presented. Meanwhile, there are multiple collisions phenomena per cycle in time history. Finally, influences of parameters on the dynamic response are studied. Note that the model in this survey may be regarded as a single-degree-of-freedom system with a friction-impact damper, which is beneficial to design nonlinear vibration absorbers based on friction and impact for the purpose of vibration suppression.

Presenting Author: Liming Jiang Beihang University

Presenting Author Biography: Liming Jiang, a PhD student of Beihang University, focuses on nonlinear vibration, rotor dynamics, aero-engine structure and intensity design, and vibration control technologies.

Authors:

Liming Jiang Beihang University
Zhimin Su AECC Hunnan Power Machinery Research Institute
Jie Hong Beihang University
Yanhong Ma BeiHang University