| Reinforced concrete beams and columns are particularly important anti-seismic component in the frame, the deformation of the component is an important characterization parameter for reflecting the performance of components good or not. Based on the conclusion of an amount of references about reinforced concrete beams ,columns and frames, the paper studies the deformation performance of reinforced concrete beams and columns under small earthquake, moderate earthquake and severe earthquake to get the deformation limit of the beams and columns by test and nonlinear finite element analysis method, which would be used in the beams and columns of existing and future frames as a indicator for the performance evaluation. The main work and conclusions are as follows:1) In the paper, 18 beams and 32 columns are designed for low cyclic loading tests, and testing process, failure mode, deformation performance of 50 specimens are carried out a detailed analysis. Force-displacement hysteresis curves, force-displacement skeleton curves , cracking load, yield load, peak load, ultimate load of beam and column specimens are obtained from the test, which provides a basis for studying the bearing capacity and deformation limits of specimens. The paper also compares the differences of concrete specimens (beam and column specimens) using small diameter CRB550 stirrups and those using HPB235, HRB335 stirrup in the bearing capacity and deformation performance. Analysis and comparison reveals that the bearing capacity and deformation performance of them are very close, which indicates that in the same longitudinal reinforcement, the CRB550 small diameter steel bar (such as 6.25mm, 7.75mm, 9.25mm) can be used to replace HPB235, HRB335 steel bar of diameter 8mm, 10mm, 12mm as the stirrups of the reinforced concrete specimens (beam specimens and column specimens).2) The test is simulated by the finite element analysis method, and the finite element simulation results are compared with the test results for load-displacement curves, failure modes and reinforcement strain. By the comparative analysis, the finite element simulation results agree well with test results, indicating that the finite element analysis method can be accurately simulate the beam and column specimens test situation.3) According to the failure types of the reinforced concrete beam specimens, 240 reinforced concrete beam specimens are designed to calculate deformation performance, and to get the deformation limit of the reinforced concrete specimen through the finite element analysis model under small earthquake, moderate earthquake and severe earthquake, and further to analyze the factors influencing the deformation limits of beam specimens. The results show that: with the increases of the main factor K value , the load-deformation skeleton curve of the specimen become cliffy from gentle, so the ductility get worse with the K value increases. As the main factorλvalue increases, the load-deformation skeleton curve of the specimen become gentle from cliffy, so the ductility get better with theλvalue increases.4) According to the failure types of the reinforced concrete column specimens, 324 reinforced concrete column specimens are designed to calculate deformation performance, and to get the deformation limit of the reinforced concrete specimen through the finite element analysis model under small earthquake, moderate earthquake and severe earthquake, and further to analyze the factors influencing the deformation limits of column specimens. The results show that: with the increases of the main factor n value, the load-deformation skeleton curve of the specimen become cliffy from gentle, so the ductility get worse with the n value increases. As the main factorλvalue increases, the load-deformation skeleton curve of the specimen become gentle from cliffy, so the ductility get better with theλvalue increases.5) Comparing the maximum deformation limits of the beam and column specimens for bending failure, bending-shear failure, shear failure with U.S. code ASCE41, the deformation limits of the United States should be relaxed than the paper. It is mainly because building materials used in the United States is better ductility than ours.6) Considering the factors influencing plastic hinge lengths of reinforced concrete beam and column specimens, statistical regression of the plastic hinge length of the reinforced concrete beam and column specimens are obtained, as well as the estimation formula of plastic hinge length of reinforced concrete beam and column specimens. Then the correlation coefficient (R-square) is used to evaluate the fit of this formula, the calculated correlation coefficient of beam and column specimens (R-square) are 90.12%, 96.36%, indicating that the estimation formula of the plastic hinge length of the beam and column specimens is suitable.
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