A Refined Numerical Simulation Study On Seismic Behavior Of Masonry-infilled RC Frame Structures

Masonry-infilled RC frame structures are the most popular structures in the modern building structures.However the earthquake occurred in recent years had caused severe damage to the masonry-infilled RC frame structures.The collapse of infilled wall can lead to serious injuries and casualties.There are a lot of reasons responsible to these severe damages,and the major reason is the lack of the knowledge of the effects on the main structure earthquake resistant behavior that the interactions between infilled walls and the RC frame structures have.The standard for earthquake of China only takes into account the effects of infilled wall on the stiffness of the overall frame in the respect of Period Time Deduction,without fully considering the interaction mechanism between infilled walls and RC frame structures.Many researchers have studied in the interactions between infilled walls and RC frame structures.The results show that the interactions can change the load transferring mechanism and the damage modes,and can also change stiffness of the frame,load capacity,ductile and the distribution of plastic hinge in the frame as well.Therefore,it is necessary to consider the effect the infilled walls have on the frame structures in the masonry-infilled RC frame structures design.In recent years,there are a lot of researchers have conducted numerous experiments and data simulation researches for masonry-infilled RC frame structures earthquake resistant behaviors.However there are few detailed modeling analyses of masonry-infilled RC frame structures.Due to the difference in materials of infilled walls,which include mortars and blocks,the researchers have to define the two material mechanical properties respectively through the different elements,and subsequently do the detailed modeling analyses for the infilled walls.Then the detailed modeling of autoclaved aerated concrete blocks and mortars will be made in this article,and the multiple factors that affect the masonry-infilled RC frame will also be analyzed.The followings are the main works of this article:(1)Use finite element analysis platform ABAQUS to establish one model of RC frame;three models of masonry-infilled RC frame by changing the ratio of reinforcement;three models of masonry-infilled RC frame by changing the axial compression ratio of frame column;three models of masonry-infilled RC frame by changing the depth-span ratio of infilled wall.(2)Use dynamic explicit analysis of ABAQUS to analyze the model of RC fame and one model of masonry-infilled RC frame,and then compare and analyze the results of the two models from 5 aspects which are hysteresis curve,skeleton curve,degeneration of rigidity,degeneration of whole strength and ductility.Results show that filled wall will increase the bearing capacity of RC frame,strengthen the energy dissipation of RC frame.(3)Use dynamic explicit analysis of ABAQUS to analyze nine models of masonry-infilled RC frame,and then compare and analyze the results of the nine models from 5 aspects which are hysteresis curve,skeleton curve,degeneration of rigidity,degeneration of whole strength and ductility.Results show that the increase of reinforcement ratio will enhance the bearing capacity of RC frame,not only can strengthen the energy dissipation of RC frame,delay the destruction of filled wall.The increase of axial compression ratio will enhance the bearing capacity of RC frame,but the excessive axial compression ratio can increase the stiffness of RC frame,accelerate the destruction of filled wall.The increase of RC frame’s span also can increase the stiffness of RC frame,accelerate the destruction of filled wall.