Experimental Study On Viscoelastic Damper Based On Different Materix Rubbers

The passive control methods are the most widely used structural vibration control technology. Viscoelastic dampers (VED) are one of effective passive control devices. Because of the advantages of simple construction, easy manufacturing, low cost and high energy dissipation capacity, VED have been widely studied and used by domestic and foreign experts. However, the production of the existing domestic viscoelastic materials is mainly used in the field of high frequency vibration control. Therefore, there are some problems of these materials, such as low energy dissipation capacity in low frequency field and low environment resistance capacity, which limits the use of these viscoelastic materials. There is an urgent need to develop a new type of high energy dissipation viscoelastic material suitable for building structure, which showed higher energy dissipation capacity in low frequency field. In this dissertation, improving the dissipation capacity of the viscoelastic materials in low frequency is the research mainlines. First of all, a series of viscoelastic materials formulation is proposed, New VEDs are designed by using these types of materials and experimental study on mechanical properties of the VEDs are carried out. Then, the mechanical model of viscoelastic damper based on higher-order fractional derivative is proposed. The research work of this dissertation is mainly manifested in the following aspects:Based on the damping mechanism of viscoelastic material, a series of viscoelastic material formulation is proposed with nitrile rubber (NBR) and silicone rubber (MVQ) as matrix. The damping performance test show that a new high energy dissipation type viscoelastic material is obtained.1) New VEDs are designed by using this type of materials and experimental study on mechanical properties of the VEDs are carried out. The effects of excitation frequencies and displacement amplitudes on mechanical properties of VEDs based on nitrile rubber and silicone rubber are studied.2) According to the microscopic mechanism of viscoelastic material, a mechanical model of viscoelastic damper based on higher-order fractional derivative is proposed. This model can simultaneously describe the influence of temperature and frequency on VED. Also, the mechanical model is verified by the comparison results between theory and experiment data.The innovation of this dissertation lies in:1) Based on nitrile rubber and silicon rubber, a new high energy consumption viscoelastic material is obtained with graft copolymerization technology. The viscoelastic material has a relatively excellent damping properties according to performance test results and damper properties test results.2) A mechanical model of viscoelastic damper based on higher-order fractional derivative is proposed. The model can accurately describe the mechanical properties of VED according to the comparison between theoretical analysis and experimental results.