Viscoelastic dampers are one of the most popular earthquake mitigation devices for building structures with a large number of applications in civil engineering. The seismic performance of viscoelastic dampers is greatly affected by viscoelastic materials. The present paper addresses the theoretical and experimental studies of the viscoelastic damper. The regular polyhedron chain network models for viscoelastic materials are proposed based on the molecular chain network microstructures and the temperature–frequency equivalent principle. Several dynamic property tests for the viscoelastic damper at different temperatures, frequencies, and displacements are carried out, and the proposed models are verified by comparing the numerical and experimental results. The comparisons show that the viscoelastic damper has perfect energy dissipation capacity, and the regular polyhedron chain network models can well describe the mechanical properties of the viscoelastic damper at different environmental temperatures and excitation frequencies.
28 August 2017 in Journal of Dynamic Systems, Measurement, and Control
Vibration is an environmental factor with hazardous effects on the instruments' precision, structural stability, and service life in engineering fields. Many kinds of energy dissipation devices have been invented to reduce the dynamic responses of structures and instruments due to environmental excitations. In this paper, a new kind of vibration isolation and suppression device with high damping performance, fine deformation recoverability, and bearing capacity for platform structures is developed, which is designed by considering the combination of the energy dissipation mechanisms of viscoelastic material, viscous fluid, and air spring. A series of dynamic properties tests on the device are carried out under different excitation frequencies and displacement amplitudes, and a mathematical model considering the coupling effects of energy dissipation of viscoelastic material, viscous liquid, and air spring is proposed. The research results indicate that the vibration isolation and suppression device has high damping capacity, and the proposed mathematical model can well describe the mechanical properties affected by excitation frequency and displacement amplitude.
16 September 2016 in Journal of Computational and Nonlinear Dynamics
This work presents an experimental and numerical study on the dynamic properties of viscoelastic (VE) microvibration damper under microvibration conditions at different frequencies and temperatures. The experimental results show that the storage modulus and the loss factor of VE microvibration damper both increase with increasing frequency but decrease with increasing temperature. To explicitly and accurately represent the temperature and frequency effects on the dynamic properties of VE microvibration damper, a modified standard solid model based on a phenomenological model and chain network model is proposed. A Gaussian chain spring and a temperature-dependent dashpot are employed to reflect the temperature effect in the model, and the frequency effect is considered with the nature of the standard solid model. Then, the proposed model is verified by comparing the numerical results with the experimental data. The results show that the proposed model can accurately describe the dynamic properties of VE microvibration damper at different temperatures and frequencies.
Viscoelastic dampers (VEDs) in seismic structures comprehensively enhance the dynamic performance of the structure by dissipating energy, providing additional stiffness and damping. The optimization analysis of dampers is the core link to ensure the safety, economy, and effectiveness of seismic design schemes. This work aims to develop low-frequency high-performance viscoelastic damping materials (VEMs) and verify the seismic control effect through three-dimensional solid engineering structure analysis. Four different damping systems of Acrylate Rubber (ACM) based viscoelastic materials were fabricated and performance characterization tests were conducted. The results indicate that all four damping modification systems can significantly improve the energy dissipation capacity of viscoelastic damping materials at low-frequency room temperature. The viscoelastic damping material with the best comprehensive performance has been selected and applied to the viscoelastic dampers of the three-dimensional shock-absorbing structure. Through the analysis of the structural vibration control effect, the universality of the vibration control effect of ACM-based viscoelastic materials under different seismic loads was further verified. It provides a feasible approach for the trans-scale research of “Material–Device–Structure” in viscoelastic damping technology.