Research On Size Effects Of Seismic Behavior Of RC T-shaped Columns

With the development of science and technology and the needs of society,the size of reinforced concrete specimens is getting larger and larger.However,due to the limitation of people’s knowledge level,external test conditions and other factors,most of the references are based on small-sized reinforced concrete specimens,which are tested and studied to obtain relevant design theories,methods and formulas.Whether extrapolation from smallsized specimens is suitable for large-sized specimens is not only new challenge to design,construction and so on,but also an urgently needed research topic.Therefore,it is necessary to carry out research on the performance and size effect of large-size specimens.This paper first carried out low-cycle reciprocating load experimental research on two reinforced concrete T-shaped columns of different sizes.The test failure process was described and analyzed in detail.According to the test results,the corresponding hysteresis curve,skeleton curve,stiffness degradation curve and energy dissipation capacity curve were obtained.Comparing the hysteresis curve and skeleton curve of these two different sizes of reinforced concrete T-shaped columns,the hysteresis curves were full and fusiform,and the skeleton curves all undergo elastic,elastoplastic and plastic processes in order.At the same time,it was inferred from the test results that the seismic performance of the reinforced concrete T-shaped column,such as the stiffness degradation and energy dissipation performance,may be related to the size effect of the specimens.Then through ABAQUS finite element software,select the reasonable concrete and steel constitutive relationship,model these two test pieces,and perform finite element analysis on them respectively.The corresponding hysteresis curve and stiffness degradation curve were obtained,and the yield load and ultimate load were obtained.Compared with the test results,the agreement was good.Parametric analysis of reinforced concrete T-shaped column specimens can be carried out by using ABAQUS finite element,which has certain reference value.In this paper,based on two specimens,two groups of eight reinforced concrete T-shaped columns are designed according to the similar proportion relationship.Study the size effect of its seismic performance by using ABAQUS finite element software.The research results show that: the eight hysteresis curves obtained by ABAQUS finite element simulation are full and asymmetric,and there are obvious pinching phenomena;As the size of the reinforced concrete T-shaped column increases,the ductility and residual deformation rate of the component decrease,and the cumulative damage index of the component increases,and there is an obvious size effect;The larger the size of the reinforced concrete T-shaped column,the faster the stiffness degradation of the early members,but the overall degradation trend is basically the same;The larger the size of the reinforced concrete T-shaped column,the higher the cumulative energy consumption,but the cumulative equivalent viscous damping coefficient is basically the same;The dimensional effect of the main seismic performance obtained by the two groups of test specimens are basically the same,which indicates that the reinforced concrete T-shaped column under axial reciprocating load has no effect on the dimensional effect of seismic performance under axial pressure.