Performance Analysis And Experimental Study Of Fabricated Pre-pressed Disc Springs Self-centering Energy Dissipation Brace

Brace is one of the commonly used anti-lateral force components in multi-storey buildings.They can also dissipate energy under seismic action,avoiding the serious damage of main structure.Self-centering energy dissipative(SCED)brace not only can dissipate seismic energy and reduce the global response of the structure,but also can nearly restore to the equilibrium position after earthquake and reduce the residual deformation of the structure,thus,the cost of component repair or replacement is reduced,improving the resilience of the structure.However,there are some problems concerning current SCED braces: For design details,assembling and disassembling are difficult,and pretension or pressure adjustment is inconvenient.For numerical simulation,the applicability of refined model and simplified model is vague and the parameters calibration is difficult.These problems prevent SCED braces from applying to the progress of building resilience in urban and rural areas.To solve the above problems,a fabricated pre-pressed disc springs self-centering energy dissipative(FPS-SCED)brace is proposed.Its mechanical properties are analyzed,and the performance of self-centering and energy dissipative are validated by quasi-static tests and numerical simulations.The main content and conclusion are as follows:(1)In view of the difficulty in assembling and disassembling of SCED brace,and the inconvenience in adjustment of prestress,as well as the problem in the selection and configuration of restoring device,a fabricated self-centering frictional energy dissipative brace is developed.In this brace,two group of disc springs are chosen as restoring device,and the pre-press is imposed by top tight bolts so as to adjust it easily.The main parts of the brace are connected by bolts to make it easy to assemble and disassemble.The mechanical property of the FPS-SCED brace was analyzed from the perspective of working mechanism,and the equations of stiffness in four stages were derived.The flag-shaped restoring force model of SCED brace was divided into a bilinear elastic model and an elastic perfectly-plastic model.The relation between restoring force and deformation of FPS-SCED brace was established for the cases with and without residual deformation.(2)In order to verify the design scheme and mechanical properties of the new type of self-restoring energy dissipation support,the self-restoring friction energy dissipation support of preloaded disc spring is processed and the quasi-static test of components is carried out.The support of the processing and assembly process are introduced firstly,and then designs the disc spring test device and the friction test device,and carried out respectively reciprocating load test,test the combination of disc spring and hysteretic characteristics of the friction mechanism.Finally,nine groups of pseudo-static tests were carried out on the self-restoring friction energy dissipation support of preloaded disc spring under different prepressures.Stable flag hysteretic curves were obtained and the design scheme was validated.The results show that the higher the initial friction is,the higher the hysteretic curve is,the more energy the support consumes.When the initial friction exceeds the pre-pressure,residual deformation of the support occurs.The support of pressure can be adjusted through bolts on both sides,with the increase of preloading,support significant increase in bearing capacity,and energy change is not obvious,that support the energy dissipation capacity and the size of the friction force,only has nothing to do with preloading.(3)Aiming at the restoration support on the numerical simulation of fine energy consumption model and the applicability of the simplified model is not clear and difficult problem of parameters calibration,professional finite element analysis was carried out based on general finite element fabricated preloading disc spring since the reduction of friction energy dissipation support numerical simulation research.In the general finite element software ABAQUS based on the principle of the reset support consumption support component refinement model is set up,through a comparison of the numerical simulation and experimental results from the point of view of numerical validation the support design and mechanical properties.In professional finite element OpenSees type based on the phenomenon of multiple stage line flag support simplified model of restoring force model,and by using the experimental data of related parameters calibration for the reduction and support structure system of the energy consumption simulation laid a foundation.