Performance-Based Multi-Stage Seismic Damage Constitutive Model And Parameter Calibration Method Of Reinforced Concrete Column

The research on the resilience of urban and rural areas needs to ensure the post earthquake functionality and recoverability of the road traffic network from the overall performance of the system.There are a large number of bridges in the road traffic network.There are a large number of bridges in the road traffic network,and the bridge damage calculation based on the refined model has high requirements for time and funds.Therefore,the research on the rapid evaluation method of the seismic capacity of regular bridges has become one of the crucial scientific problems to be solved urgently.The column under linear elastic force of regular bridge can be simplified into a single degree of freedom model to calculate,while the analysis of inelastic and elastoplastic pier under earthquake needs to establish a complex nonlinear model to calculate its seismic performance.In this paper,the ductile pier is equivalent to a single degree of freedom model with elasticplastic constitutive.The multi-dimensional power function model of section hierarchical curvature is established,and then the seismic multi-level damage model of member hierarchy is deduced and calibrated by theoretical method.In order to achieve this goal,the main research of this paper is as follows:1.A parametric moment-curvature approach combining discrete reinforcement continuous treatment,section dimensionality reduction and variable interval integral approach is proposed.The discrete reinforcement continuous treatmen simplifies the detailed reinforcement information(diameter,spacing,etc.)to only the physical information of reinforcement ratio while maintaining accuracy.The section dimensionality reduction simplifies the section to a one-dimensional model with material thickness information,which significantly improves the calculation efficiency.The variable interval integral approach uses different curvature increments for different curvature intervals to further improve the calculation efficiency.Finally,the moment curvature curve can be obtained only by inputting the crucial parameters of the section to calculate the moment-curvature curve.Combined with the definition of damage state,the curvature and curvature ductility of the corresponding is obtained.The comparison with experimental data and xtract shows the excellent accuracy of this method.2.Based on the parametric moment-curvature approach,a decoupled multidimensional power function model(UCMV-PM)is established.By inputting four crucial parameters of the section,the curvature and curvature ductility in four damage states can be efficiently obtained.Profit from the high efficiency of the parametric-moment-curvature approach,the sample space of 21~4 limit curvature,i.e.194481 levels,is established.The influence ability of crucial parameters in slight and moderate damage state is:section size,axial compression ratio,reinforcement ratio and stirrup ratio from high to low,while stirrup ratio in extensive and collapse damage has a stronger influence,second only to section size.The verification,comparison and application of UCMV-PM show that it has high precision,strong practicability and wide coverage.3.Based on UCMV-PM,the high-strength concrete and high-strength reinforced pier is further researched,and the corresponding empirical capacity model is advanced.Based on the parametric moment curvature method,the sample space of 11~6 limit curvature considering bucklingt,i.e.1771561 levels,is established.The analysis of the crucial parameters shows that the concrete strength has the most significant influence,followed by the stirrup ratio,section size,axial compression ratio,reinforcement ratio and reinforcement yield strength,but the reinforcement yield strength has a great influence on the ultimate curvature ductility.The influence of limit curvature without considering buckling effect and considering buckling effect on each parameter maintains a similar change trend,and the ratio of the two has been maintained at about twice.4.Based on UCMV-PM and plastic hinge model,the seismic multi-level damage constitutive model is proposed.The model can efficiently obtain the trilinear constitutive model of components by inputting several crucial parameters.The trilinear constitutive model can not only accurately simulate the hysteretic curve and displacement time history under actual seismic waves,but also highly agree with the pushover analysis results of the test which proves that the model is efficient,easy to operate and accurate.Based on the parametric moment-curvature method,the UCMV-PM and empirical capacity model are established.The seismic multi-level damage constitutive model is derived by using the theoretical method,which can be applied to the rapid evaluation of the seismic capacity of regular bridges in the road traffic network.