Numerical Modeling Of Structural Behavior Of Exsiting Reinforced Concrete

As the service time, the performance of city's existing reinforced concrete buildings continue to deteriorate, affect the safe use of the structure, attenuate its intended function. Study the performance of existing reinforced concrete structures can not only reveal the potential risk, but research also can be directly used to guide the structural design.In this paper, against the background of having a lot of cities'existing buildings in China, using artificial neural network model and finite element analysis software OpenSEES as a tool, from the materials, components and overall structure of the three levels to study existing concrete structure of the performance of the city.First, on the basis of summarize and analyze the research results of prediction of concrete strength results concrete strength, using MATLAB neural network toolbox, established the degradation model of concrete strength of existing buildings to study the performance degradation of the existing building materials. The model in this paper mainly considers the degradation of concrete strength with time rules, the results can be used to survey a large area of the seismic performance of existing buildings.Second, based on a large number of shear test data abroad, using the neural network model to study the components of reinforced concrete beam shear properties. Shear design of the national standard method and neural network prediction method were compared, the results show that this neural network model has good accuracy, its results significantly better than the experience and theoretical calculation formula.Finally, a three-span and 10 layers reinforced concrete frame was built in OpenSEES with fiber model, by pushover analysis to study the mode of casting slab on the impact of structural damage. Whether to consider casting slab or not, two conditions is divided, and respectively carry on Static Analysis. The presence of cast slab weakened design expected "strong column and weak beam" effect.Through study of this article, we can effectively reveal degradation laws of existing buildings'material and component, and the affect of cast slab on the seismic capacity of the whole structure.