| At present,China is actively promoting the transformation and upgrading of the construction industry.As an important grasp of building industrialization,prefabricated buildings have received full attention.As an anti-seismic member that can resist horizontal load and control lateral deformation,prefabricated concrete shear wall structure is widely used in medium and high-rise buildings.However,due to the large damage and residual deformation of the traditional concrete shear wall under an earthquake,it is difficult to repair their damage after an earthquake.In addition,the construction is complex with large environmental pollution.Scholars at home and abroad put forward the structural form of self-centering concrete shear wall.This paper comprehensively considers the seismic design idea of "performance-based",and proposes a new type of multi-level energy dissipation hybrid connection fabricated concrete shear wall,by combining plural energy dissipators with the traditional self-centering shear wall structure,which improves energy dissipation capacity and realizes graded energy dissipation.For the proposed new structure,this paper has carried out in-depth research,and the main contents are as follows:(1)Two graded energy dissipation mechanisms of the new shear wall structure are proposed,and its ideal skeleton curve and restoring force model are analyzed in detail.Combined with a buckling restrained brace energy dissipation device(energy dissipation rod)and metal shear energy dissipation steel plate proposed by the author’s research group,the specimens are designed with different graded energy dissipation mechanisms,and their design process and specific structure are introduced in detail.(2)Three groups of low cycle reciprocating load tests under different working conditions are carried out for the designed specimens.Different forms of energy dissipators are arranged under the three working conditions.The test phenomena are analyzed in detail.According to the experimental data,the key seismic performance evaluation indexes such as hysteretic curve,skeleton curve,strength,ductility ratio,strength and stiffness degradation,energy dissipation capacity and self-centering capacity are obtained,The analysis results show that compared with the traditional self-centering shear wall structure,the new self-centering shear wall structure with energy dissipation device has fuller hysteretic curve and improved energy dissipation capacity.By setting the energy dissipation rod and shear energy dissipation steel plate,the effect of graded energy dissipation can be realized while improving the seismic performance of the structure.The secondary stiffness model controlled by Belleville spring and the three fold line model without Belleville spring is verified in the test.After the test,the damage is found to concentrate in the energy dissipation device with less damage to the main structure,and the repairability of the structure after the earthquake is greatly improved.(3)The numerical model of the specimen is established and analyzed through the finite element analysis platform OPENSEES,and its results under the low cycle reciprocating load of the test are simulated.It is compared with the test results to verify the rationality of the numerical model.Based on the established numerical model,the parametric analysis of the initial prestress,the sliding distance of Belleville spring and the thickness of shear energy dissipation steel plate is carried out,and the influence laws of the above parameters on the overall seismic performance and graded energy dissipation mechanism of the structure are obtained,which provides a basis for the further optimization of the shear wall structure.Based on the above work,this paper makes a more in-depth study on the seismic performance of the new multi-level energy dissipation hybrid connection fabricated concrete shear wall structure,summarizes the test results and finite element calculation and analysis,and puts forward the prospect for the problems that need to be studied. |
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