| The seismic performance of assembly architecture has always been the focus of the study.The assembly frame structure is damaged by the earthquake action,and the strength and stiffness of the component are degraded in varying degrees because of the damage.Although the aseismic capability of the structure is decreasing under earthquake,it does not mean that the structure will fail,and the structure still has some residual bearing capacity.For the structures that have not collapsed and have a suitable repair after the earthquake,the reconstruction of them will not only affect the normal work and life of the people,but also cause huge economic waste.It is due to the multiple occurrence of the earthquake in China and the continuous use of most of the earthquake damage structures after the repair,so the assembly type of steel is coagulant*Post earthquake performance evaluation of soil frame structures is very necessary.The research work is carried out under the support of the national,"12th Five-Year"science and technology support program(2015BAK14B02-6)"post earthquake performance evaluation method based on structural damage monitoring":(1)as one of the characteristics of the structure,the neutral axis is easy to measure and has the ability to determine the damage quantitative.It has been applied in the steel structure,the shield tunnel and the bridge.In this paper,the structural characteristics of the neutral axis are introduced to the damage assessment of the assembly frame joints,and the damage assessment theory of the assembly frame node based on the neutral axis movement is established.The core principle of the evaluation theory is to determine the average neutral axis position of the plastic hinge region by measuring the average curvature of the plastic hinge area according to the assumption of the flat section,and then to define the damage degree of the plastic hinge by the rotational degree of the plastic hinge,and then evaluate the performance of the assembly frame.(2)by establishing the pseudo static experiment of the node finite element model in the assembly frame and the nodes in the two assembly frame,the results of the finite element analysis and the analysis of the node experiment are applied to the evaluation of the results of the evaluation theory and the theory of single parameter damage assessment based on the deformation,stiffness and energy,as well as the traditional double parameter damage.The evaluation results of the evaluation theory verify the reliability of the damage assessment theory in this paper.(3)this paper presents a theory of damage assessment for the whole assembly frame,that is to quantify the damage of each layer of the frame through the weakest plastic hinge between the assembly frame layer,and consider the weight coefficient of each layer of the frame at the same time to get the damage of the whole frame of the assembly frame through the damage weighting.The main steps of the evaluation theory are as follows:?determining the hinges of the beam column combination according to the flexural bearing capacity ratio of the beam end and the column end;?calculating the plastic rotation capacity of the plastic hinges of each floor of the frame structure;?determining the weakest plastic hinge of the various floors;?to quantify the damage of the frames according to the rotation degree of the weakest plastic hinge;?The damage level of the fabricated frame is obtained by the method of inter layer weighting.?According to the overall damage volume of the fabricated frame and combined with the classification standard of the corresponding frame failure grade,the damage grade of the structure is determined.(4)By establishing the finite element model of two layer two span cast in place column frame and referring to the pseudo static experiment of two layers and two span cast-in-situ beams in the existing literature,the reliability of the damage assessment theory is verified by the analysis of the finite element and experimental results respectively. |
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