Multi-scale Finite Element Modeling And Numerical Analysis Of Reinforced Concrete Structure

Structural multi-scale finite element analysis, as an effective process to obtain appropriate balance between accuracy requirements and calculation workloads, is a method that may couple the efficient coarse elements and the accurate refined elements in a model. And this method makes it possible to analyze the local damage in large scale structure. To accomplish a reliable interface between refined element model and coarse model, different methodologies are proposed in general finite element software ABAQUS, and some simple models are calculated to verify the methodologies. The word done in this dissertation was listed as follows:(1) Distinct types of structural multi-scale finite element analyses are presented, including interface connection between the same type of elements and distinct types of elements. Different coupling methods in general finite element software ABAQUS are introduced. Through the coupling methods above, a reliable interface between refined element model and coarse model can be established. Also some simple models are calculated to verify the methodologies.(2) Some questions of different type of elements simulations are presented, for example different concrete constitutive models and simulation of rebar, which is significant to establish a reliable interface between refined element model and coarse model And it is very meaningful for large structural finite element analyses. The coupling method is shown in chapter two. A simple cantilever beam model is calculated to verify the method. From simulation results, it is shown the effect is excellent. The displacement and stress time history of three distinct models are very similar. Simulations of multi-scale model are more similar to refined model. As for computational time, simulations of multi-scale models are more efficient.(3) Two simulations are shown to illustrate the application of multi-scale finite element analysis in practical engineering. Seismic response of frame structure and shear wall structure simulations are presented. The location and simulation of vital members or nodes are discussed, also the local damage analysis is presented. In simulation of frame structure, beam element is used for beam and column member, while in simulation of shear wall structure, shear element is used for plate and wall member. Through seismic response of these two models, the location of vital members and nodes can be clear. And solid element is used for the vital member. There exist not just one coupling methods in the two multi-scale models, including MPC, solid to shell coupling and so on. All these methodologies are shown in chapter two. Compositive analyses of two different models (coarse model and multi-scale model) are shown, including mode analysis and elastic-plastic dynamic response analysis.