Study On Seismic Performance Of Damage-controlled Frame-plastic-hinge-supported Wall Structure

Earthquake Resilience has become one of the most important indices in the seismic performance assessment of modern buildings.The reinforced concrete shear wall,as the most improtant component to resist the lateral seismic force in high-rise buildings,has been found lack of resilience during recent severe earthquakes.Major damages were observed on the coupling beams and the bottom parts of shear walls,which are deemed irrepairable.To this end,this study proposed two novel compoents,namely an energydissipating coupling beam with metallic dampers and a plastic hinge-supported wall.The design methods and numerical simulations are conducted,and the strength and stiffness demands are discussed by a generic model based on the continuum method.Primary research contents and conclusions are stated as follows:1.Experimental data of hundreds of reinforced concrete coupling beam or shear wall specimen tests were collected and analyzed.A weak correlation between the deformability and the design parameters are observed.2.The energy-dissipatiing coupling beam using steel dampers with slits was proposed.Experiments were carried out on the traditional RC coupling beam and the energy dissipation coupling beam with the same aspect ratio of 3.0.The results were compared and indicate that the design equations of both specimens are able to predict the test results.The energy dissipation coupling beam has a better performance in controlling seismic damages,because the metallic damper yield earlier thus protecting concrete parts being damaged.More than 80% of the deformation was concentrated in the steel damper with slits,fully taking the advantange of metallic dampers of large capacity of energy dissipation.There exists slippage at the surfaces between the damper and the RC coupling beam,which mitigate the effectiveness of the metallic damper.Finally,a simplified numerical model was established and its adaptability was demonstrated by the test data.3.A damage-controled plastic-hing-supported wall was proposed to explicitly decouple the complex bending-shear coupling mechanism.The design equations about the stiffness and strength were developed and have been demonstrated accurate to predict the mechanical behavior.The comparison between the traditional RC wall and the proposed wall specimen indicate that the plastic-hinge-supported wall has better deformationability and energy dissipation ability.The flexural deformation took the primary part of the total deformation so as to prevent the wall from the fragile shear failure,thus realizing the favorable strong-shear-weak-bending design concept and avoiding the irreparable failure of RC walls.4.Parameter analyses of the plastic-hinge-supported wall were performed based on a simplified numerical model where,fiber elements with shear performance section aggregation were used to simulate the reinforced concrete shear wall,and the zeroLength element was used to describe the nonlinear behavior of the elastic-designed connections of BRBs.The feasibility and accuracy of this model were examined by the results of pseudo-static loading tests.The parameters such as the aspect ratios r of width to height,? of the height of the pin-supporter to the height of the wall,the axial compression ratio ?,and the initial axial stiffness of BRB's plastic segment,Ked,were analyzed.It is concluded that the performance of dampers is primarily controlled by the geometrical parameters,the plastic-hinge-supported wall are suggested for the bottom part of shear walls,and the ratio r is better to be limited less 1.0,while the ratio ? should be less than 0.6.A greater ratio ? and the higher damper stiffness Ked are helpful to increase the bearing force and stiffness of the wall,if the demand of ultimate strain of damper has been satisfied.5.The continuum analytical method was used to analyze the responses of the plastichinge-supported wall structure and the plastic-hinge-supported wall-frame structure considering three typical lateral loading profiles.The results show that the continuum method is applicable for acquiring the structural response of plastic-hinge-supported wall structures.The equations of stress and deformation show that the structural performance is significantly affected by the plastic-hinge-supported wall members.