MODELING OF MASONRY INFILL PANELS FOR STRUCTURAL-ANALYSIS

An analytical macromodel based on an equivalent strut approach integra ted with a smooth hysteretic model is proposed for representing masonr y infill panels in nonlinear analysis of frame structures. The hystere sis model uses degrading control parameters for stiffness and strength degradation and slip ''pinching'' that can be implemented to replicat e a wide range of hysteretic force-displacement behavior resulting fro m different design and geometry. The paper presents the development of the hysteretic model and the definitions of the control parameters, w hich can be determined using any suitable theoretical model for masonr y infills. An available theoretical model for simplified engineering e valuation of masonry infilled frames was explored for estimating the c ontrol parameters of the proposed macromodel. The macromodel was incor porated in a nonlinear structural analysis program, IDARC2D Version 4. 0, for quasi-static cyclic and dynamic analysis of masonry infilled fr ames. Simulations of experimental force-deformation behavior of protot ype infill frame subassemblies are performed to validate the proposed model. A lightly reinforced concrete frame structure is analyzed for s trong ground motions to evaluate the influence of masonry infill panel s on the dynamic response.