Micro And Macro Finite Element Simulation And Seismic Performance Analysis Of Reinforced Concrete Frames Infilled With Masonry Walls

The reinforced concrete frames infilled with masonry walls exsit broadly inmany areas prone to strong earthquakes. There has been much damage of this kind ofstructures in many severe earthquake events. There are a lot of reasons for the severedamage of RC frames infilled with masonry walls in strong earthquakes, one of whichis the unreasonable design method and practice. Furthermore, there still lacks ofscientific understanding of the interaction principle between the masonry walls withRC frames.Based on the above considerings, in this thesis, two secondary developed finiteelement software, the FEAP developed by prof. Robert L. Taylor in the University ofCalifornia at Berkeley, and OpenSees funded by NSF of America, lead by PEER anddeveloepd by UC Berkeley, are chosen as the simulation platforms. The micro andmacro finite element models for reinforced concrete frames infilled with masonrywalls are built respectively. The crack and stress development trend and theinteraction mechanism between masonry walls and RC frame are studied thoroughly,and the seismic performance of RC frames infilled with masonry walls is analyzed.The main contents are as follows:(1) Based on the secondarily developed FEAP, the micro finite element modelsare built for RC frames infilled with masonry walls combing the smeared crackapproach and the discrete crack one. Then, a RC frame model in UCSD has been usedto validate the rationality of the modeling methodology, as well as the accuracy of thesecondary development program. Using the validated FEAP program, a single-storyand single-bayframe, and a multi-story multi-bay shaking table frame model, areestablished with the micro finite element methods respectively. Then the pushoveranalyses are performed on the two models. The trends of crack development andstress development are observed, and the interaction mechanism between infill wallsand RC frames is studied.(2) Based on the platform OpenSees, the macro finite elementmodels are set upfor RC frames infilled with masonry walls with the equivalent diagonal brace model.Then the pushover analysis is carried on on the models. Comparing the results by micro finite elements with those by macro finite elements, it has been observed thatthe macro elements can not accurately describe the decline of the carrying capacityafter cracking. Then, the macro finite element model is modified by the results of themicro finite element model. Using the modified macro finite element model, thenonlinear time history analysis is performed on the space RC frame model for shakingtable tests. Comparing with shaking table test results, the rationality of the modifiedmodel is verified.(3) The orthogonal design method is used for parametric analysis schemes.Theinfluencing laws of brick strength, aspect ratio, height to thickness ratio, as well asother parameters, on the seismic performance of RC frames infilled with masonrywalls are systematically studied. Through range analysis and analysis of variance(ANOVA), the sensitivities and the sequences of the different parameters are derived.Finally, the regression relationships of structural stiffness and strength with storeynumbers and aspect ratio are given respectively.