| The study of nonlinear constitutive relations of frame structures is a hot topic in engineering research in recent years,This paper is a study of nonlinear reliability of frame structures under strong earthquakes.However,there are many problems in current research methods,such as huge computation,dificult selection of seismic wave,numerous parameters of dynamic model and simplified model,so it is difficult to operate.The nonlinear research methods of this paper is to use the static elastic-plastic Pushover analysis method is a kind of seismic wave structure deformation constitutive relation method,This method solves many problems mentioned above,simplifies the process,and has good practicability.Therefore,more and more attention has been paid to it.The programming of Pushover method is operated on the OpenSEES software,and then the improved version of dimension reduction method is used to make the reliability analysis of the structural model after the analysis of the Pushover method.The full text contains the following parts:(1)The specific operation process of the elastoplastic Pushover analysis method is introduced through the literature at home and abroad,several Pushover analysis methods for elastoplastic nonlinear frame structures are listed,the anti seismic design idea based on Pushover analysis method is expounded.(2)Combined with self compiled program,node model is applied to simulate the response of beam column joints of reinforced concrete frame structure under static elasto-plastic interaction and dynamic time history seismic wave.In the process of simulation,the composition of the OpenSEES program,the related commands,and the materials and unit types involved in the analysis are introduced.A graphical program for visual data research based on Matlab software is compiled.The relation curve of hysteretic characteristics of the shear and displacement of the complex structure is obtained.(3)The frame structure is parameterized and the reliability analysis is carried out.Through some literature at home and abroad,we know the method of reducing dimension analysis in the method of reliability moment,and the calculation precision Weifa drop higher moments of the traditional calculation and Monte Carlo simulation method and the failure probability of error is large compared.Therefore,the calculation accuracy of the innovative method of multiplicative dimension reduction(M-DRM)is close to the results of the Monte Carlo simulation(MCS)calculation.Furthermore,the multiplicative dimension reduction method(M-DRM)is used in the calculation of structural reliability.(4)Based on the reliability calculation method of the elastoplastic structural framework proposed above,a system program for solving dynamic reliability problems of frame structures under strong earthquake loads is formed.Several two-dimensional and three-dimensional complex structural frameworks are selected for reliability analysis.The probability distribution function(PDF),the probability of exceedance function(POE)and the cumulative distribution function(CDF)of the most dangerous nodes of the parameterized model are obtained.And compared with Monte Carlo simulation,the relevant conclusions are obtained.Research shows:The accuracy of the M-DRM method is similar to the reliability of the Monte Carlo simulation method,and the accuracy of the calculation is similar,the relative error of calculation is within 1%.However,the computation time has been greatly reduced,which is generally within 10%of the computation time of Monte Carlo simulation method,and the computation cost has been greatly reduced at the same time. |
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