Experimental Study And Finite Element Simulation Of Sector Visco-elastic Damper

By studying the research status and application examples of viscoelastic dampers both at home and abroad,we have designed and developed sector visco-elastic damper that combines the requirements of shape,appearance,processing quality,main material properties,mechanical properties and durability,Sector viscoelastic dampers(SVED)with independent intellectual property rights.This type of damper has significant advantages such as energy dissipation,support frame beam,transmission shear force,positioning limit,it can well enhance the seismic strength of the frame structure joints.The key step in the design and manufacture of SVED is the design and processing of the mold.The performance of the rubber material and the vulcanization technology of the rubber and the steel plate are the key factors affecting its performance.The main characteristics of rubber materials are superelasticity and viscoelasticity.The rubber materials used in this study are subjected to uniaxial tensile tests,stress relaxation tests,DMA experiments,and bond strength tests.Through the uniaxial tensile test and adhesive strength test of rubber material,the maximum elongation of rubber material is 600%,the maximum tensile strength can reach 22 MPa,and the average maximum adhesive strength of rubber and steel plate is 6MPa,and it is sticky.The destruction type of the joint is peeling damage.Through the DMA test,the storage material's storage modulus(G'),loss modulus(G'')and loss factor(?)were measured as a function of temperature and frequency.In order to study the performance of SVED such as energy dissipation performance,skeleton curve,fatigue performance,and maximum deformation ability,as well as load amplitude,loading frequency and other factors,two SVEDs were designed for low-cycle repeated loading tests.Through the study found that: From the changes in the skeleton curve can be found that the mechanical properties of SVED mainly depends on the performance of rubber materials.When the strain amplitude is small,the loading amplitude of SVED has little effect on the stiffness of the damper.With the increase of strain amplitude,the maximum load of SVED increases,the hysteresis loop area increases but tends to become less full,the energy dissipation coefficient decreases,and the equivalent damping ratio does not change significantly.The maximum load of SVED did not change significantly under three different loading frequencies.The hysteresis loop exhibited a layered envelope phenomenon.The larger the loading frequency,the larger the hysteresis loop area.The higher the loading frequency,the higher the energy dissipation factor and the equivalent damping ratio of SVED,and the same trend of change at different loading frequencies.The fatigue performance of SVED is good.In the repeated loading process,the shape of hysteresis curve is consistent,and there is no obvious hysteresis curve area attenuation and low cycle fatigue phenomenon.The failure type of SVED at the strain amplitude close to 300% is the interfacial tearing failure,which indicates that the SVED has reached the ultimate shear strength.The finite element analysis of SVED was performed using ABAQUS.The skeleton curve obtained from the simulation experiment and the skeleton curve obtained from the experiment showed the same trend when the loading amplitude was small.The simulation results showed that the stiffness variation law of rubber was similar to the stiffness variation rule measured by the performance test..During the increase of rubber stress,the stress distribution pattern of rubber did not change,and the bottom deformation was the largest and the shear stress suffered was the largest.The effect of loading amplitude and loading frequency on the hysteretic energy,energy dissipation,and equivalent damping ratio of SVED are the same as those of the performance test.