Research On OpenSees Based Substructure Pseudo-dynamic Test For Bridge Considering Multi-point Excitation Effect

Sub-structure quasi-dynamic test is one of the most important research methods in engineering seismic field,which is helpful to study the seismic performance of large-span and large-size bridge structures.The test method not only reflects the structural response of the earthquake,but also reduces the cost of the test.OpenSees,as an open source finite element software,has good operating characteristics,and its efficient computing speed and reliable computing accuracy have become a research tool for many researchers,and a high degree of open source features for sub-structure quasi-dynamic test secondary development software Maybe.In this paper,the pseudoSees sub-structure pseudo-dynamic test method research and related program development are carried out,and a virtual sub-structure pseudo-dynamic test of a four-span beam bridge is completed,and the virtual sub-structure pseudo-dynamic test under the multi-point excitation is carried out.Research and verify the feasibility and effectiveness of the whole method.Firstly,the basic principle of sub-structure quasi-dynamic test is introduced,the running framework of OpenSees and the whole process of sub-structure quasi-dynamic test using Tcl scripting language are introduced.At the same time,the theory of elasto-plastic time history analysis is expounded.The theory of numerical integration method,the nonlinear beam-column element,cross section and its equation solution in OpenSees.These are the theoretical basis for the follow-up program development.Then the theoretical analysis method of pile-soil interaction and its partial calculation simplified model are introduced.The difference between m method and py curve method is compared and how the py curve method is used in OpenSees to describe and calculate it.The feasibility of the quasi-dynamic test method of sub-structure considering pile-soil interaction is verified by taking the middle part of the beam bridge as an integral part and taking it as the experimental sub-structure.Finally,the related theoretical methods of multi-point excitation and the method of generating artificial seismic waves under the method are introduced.A bridge with a span of 100m and a single span of 185m is taken as an example.And the response method of the multi-point stimulus input is applied.At the same time,the multi-point incentive analysis method is applied to the previous sub-structure quasi-dynamic test method.The results show that the sub-structure pseudo-power The test method is also applicable in the multi-point excitation analysis method.