Research On Mechanical Properties Of Three-dimensional Metal Dampers And Application In Reticulated Shell Structures

At present,the existing traditional dampers are mostly used for energy dissipation in the horizontal direction of engineering structures,and it is difficult to meet the multidimensional energy dissipation requirements of spatial structures.The research group has developed a new three-dimensional metal damper in the early stage,that is,adding an S-shaped element inside the U-shaped metal damper to improve the multidimensional energy dissipation capability of the damper.This paper further conducts research on the basis of the previous work of the research group.The main research contents and results are as follows:(1)Experimental study on mechanical properties of three-dimensional metal dampers.One U-shaped and three three-dimensional metal damper specimens were processed and fabricated,and one-way and two-way quasi-static tests were carried out.The results show that the hysteresis curves of the three-dimensional metal damper are symmetrical and plump under the horizontal and vertical one-way loading,showing stable and good hysteresis performance;the horizontal and three-dimensional metal dampers under the horizontal and vertical two-way loading are relatively more horizontal hysteresis curves.Regular,symmetrical and uniform,and the vertical hysteresis curve is asymmetric;under two-way loading,compared with the U-shaped metal damper,the vertical and horizontal energy dissipation capacity of the threedimensional metal damper is close,which can better meet the seismic action.Multidimensional energy consumption requirements of space structure.(2)Finite element analysis of mechanical properties of three-dimensional metal dampers.ABAQUS finite element software was used to analyze the hysteretic performance of the three-dimensional metal damper under different horizontal direction loading,bidirectional different proportional loading and different path loading.The results show that the horizontal loading in different directions has little effect on the energy dissipation capacity of the three-dimensional metal damper;when the horizontal loading is greater than the vertical loading,the horizontal energy dissipation capacity of the three-dimensional metal damper under different proportional loading is close,and the vertical energy dissipation capacity is different.When the loading ratio is horizontal: vertical = 2:1,the horizontal hysteresis curve under different path loading is close to the one-way loading hysteresis curve,and the vertical hysteresis curve is quite different from the one-way loading hysteresis curve.And the hysteresis curves under different path loading are quite different.(3)The calculation formula of mechanical performance index of threedimensional metal damper is established.The calculation formula of the mechanical performance index in the elastic stage of the U-shaped and S-shaped elements of the three-dimensional metal damper under the action of unidirectional load is deduced.The calculation formulas of yield bearing capacity,elastic stiffness and post-yield stiffness ratio of U-shaped and S-shaped elements in elastic-plastic stage are compared with the experimental results,which show that the theoretical calculation formula has good accuracy.(4)Application of three-dimensional metal dampers in reticulated shell structures.The three-dimensional metal damper is applied to the reticulated shell structure.Based on the principle that the horizontal restoring force of the three-dimensional metal damper is equal to the viscous damping force,the preliminary design of the threedimensional metal damper is carried out,and its shock absorption effect on the reticulated shell structure is analyzed.The results show that compared with the Ushaped metal damper,the three-dimensional metal damper has better shock absorption effect on the displacement of the isolation bearing,which can be increased by 33.7%;The average damping rates of rod stress are 73.5%,71.2% and 48.8%,respectively,which effectively reduces the seismic response of the reticulated shell structure and protects its seismic safety.