The Numberical Simulation Researth On Substructure Interface Simulation Method Based On Inflection Point

Substructure test method is a hybrid test method, only the key parts of structuredone physical test in the laboratory, the other parts are simulated by finite elementmethod simulation. In recent years, with the application of network technology,achieveing test substructures and numerical substructures situate different laboratory,and make the distributed substructure test come true, and then greatly shar e theresource of per laboratory, which is an economically rational, broad applicationprospects of test method. The interface simulation is the core issue of substructuretest, in recent is still in the preliminary study stage and severely restricted thepromotion and application of substructure test methods. Based on these, the paperbegains with conventional substructure interface simulation and proposesubstructure interface simulation method which based on inflection point, to donumerical simulation analysis by open source finite element analysis software ofOpenSEES, studies have shown the feasibility of the proposed scheme.Firstly, the paper carried out numerical simulation and compared twotraditional substructure simulation methods, considering the full factor interfacesimulation method with two interface simulation methods of based inflection point,all based on shear-type structure. As shown in the results, the traditional method ofdoing not consider overturning moment under condition of almost pure shear-typestructure, whether macro-displacement and hysteresis curves or internal forces areshowing bigger errors. The displacement and hysteresis curves of traditional methodof considering overturning moment are improved a little, but the error is still large.Considering the full factor interface simulation method considers all information onthe interface(include moment,shear and aixial force), which can almost get the sameresult as precise value, but the simulation of moment is difficult to realize actualoperation, lead to achieve difficultly in present load testing equipment technology.We propse two simulation methods based on inflection point have roughly equalerror with considering the full factor interface simulation method, are good at usingthe properity of inflection point to avoid interface moment and own goodoperability.Then, based on above study, for curved scissors-type model, using uniform design test program, under case of considering the different floors, spans, peak ofground acceleration and linear stiffness ratio of beam-column, carried out acomparative study of numerical simulation and the corresponding error analysis forabove methods, the simulation results show, as can be see from the time curves ofdisplacements and internal forces (shear, moment, axial force) and hysteresis curvesfor curved scissors-type model, proposed simulation method based on inflectionpoints have similar conclusions with shear-type model, and errors have greaterimprovement than conventional simulation methods. Particularly, the secondmethod has better maneuverability and feasibility. As can be seen from cumulativeerrors and regression analysis, the errors of two methods based on inflection pointare smaller and improvement compared to conventional method. From theregression analysis of displacement, internal forces and four factors known that peakof ground acceleration is the main factor of displacement and internal forces forconventional method of doing not consider overturning moment; Every factor is nota simple one-factor-related with conventional method of considering overturningmoment and also about the cross-term; Peak of ground acceleration is the mainfactor of displacement and internal forces for method one based on inflection point;Displacement error is positive cross-correlation with peak of ground acceleration,shear and moment are positive cross-correlation with linear stiffness ratio ofbeam-column, axis force error is positive cross-correlation with structural layers andnumbers for method two based on inflection point.