Evaluation of infilled frames: an updated in-plane-stiffness macro-model considering the effects of vertical loads

The influence of masonry infills on the in-plane behaviour of RC framed structures is a central topic in the seismic evaluation and retrofitting of existing buildings. Many models in the literature use an equivalent strut member in order to represent the infill but, among the parameters influencing the equivalent strut behaviour, the effect of vertical loads acting on the frames is recognized but not quantified. Nevertheless a vertical load causes a non-negligible variation in the in-plane behaviour of infilled frames by influencing the effective volume of the infill. This results in a change in the stiffness and strength of the system. This paper presents an equivalent diagonal pin-jointed strut model taking into account the stiffening effect of vertical loads on the infill in the initial state. The in-plane stiffness of a range of infilled frames was evaluated using a finite element model of the frame-infill system and the cross-section of the strut equivalent to the infill was obtained for different levels of vertical loading by imposing the equivalence between the frame containing the infill and the frame containing the diagonal strut. In this way a law for identifying the equivalent strut width depending on the geometrical and mechanical characteristics of the infilled frame was generalized to consider the influence of vertical loads for use in the practical applications. The strategy presented, limited to the initial stiffness of infilled frames, is preparatory to the definition of complete non-linear cyclic laws for the equivalent strut.

[1]  Xin Zhao,et al.  Study on Finite Element Model of Infilled Walls of Steel Frames , 2011 .

[2]  Panagiotis G. Asteris,et al.  Lateral Stiffness of Brick Masonry Infilled Plane Frames , 2003 .

[3]  P. Asteris.  Finite Element Micro-Modeling of Infilled Frames , 2008 .

[4]  B Stafford Smith,et al.  A METHOD OF ANALYSIS FOR INFILLED FRAMES. , 1969 .

[5]  D. Abrams.  Proceedings from the NCEER Workshop on Seismic Response of Masonry Infills : held at the Holiday Inn Golden Gateway, San Francisco, California, February 4-5, 1994 , 1994 .

[6]  P. Benson Shing,et al.  Analysis of Seismic Response of Masonry‐Infilled RC Frames through Collapse , 2014 .

[7]  Amin Mohebkhah,et al.  Mathematical micromodeling of infilled frames: State of the art , 2013 .

[8]  B Hobbs,et al.  Inelastic Design of Infilled Frames , 1995 .

[9]  K. Willam,et al.  Numerical modeling of masonry-infilled RC frames subjected to seismic loads , 2011 .

[10]  K. C. Stylianidis,et al.  Experimental Investigation of Masonry Infilled R/C Frames , 2012 .

[11]  Liborio Cavaleri,et al.  Cyclic response of masonry infilled RC frames: Experimental results and simplified modeling , 2014 .

[12]  Francisco J. Crisafulli,et al.  PROPOSED MACRO-MODEL FOR THE ANALYSIS OF INFILLED FRAME STRUCTURES , 2007 .

[13]  Panagiotis G. Asteris,et al.  Mathematical Macromodeling of Infilled Frames: State of the Art , 2011 .

[14]  Richard M. Bennett,et al.  In-Plane Analysis of Masonry Infill Materials , 2001 .

[15]  Liborio CAVALERI,et al.  EFFECT OF VERTICAL LOADS ON LATERAL RESPONSE OF INFILLED FRAMES , 2002 .

[16]  G. C. Manos,et al.  The behavior of masonry assemblages and masonry-infilled R/C frames subjected to combined vertical and cyclic horizontal seismic-type loading , 2012, Adv. Eng. Softw..

[17]  K. Bath,et al.  ON THE CONSTRAINT FUNCTION METHOD FOR CONTACT PROBLEMS , 2003 .

[18]  Panagiotis G. Asteris,et al.  Modeling of Infilled Frames With Openings , 2012 .

[19]  Giuseppina Amato,et al.  AN UPDATED MODEL OF EQUIVALENT DIAGONAL STRUT FOR INFILL PANELS , 2009 .

[20]  Liborio Cavaleri,et al.  Infilled frames: developments in the evaluation of cyclic behaviour under lateral loads , 2005 .

[21]  Alessandra Fiore,et al.  The influence of masonry infill on the seismic behaviour of RC frame buildings , 2012 .

[22]  Liborio Cavaleri,et al.  A new dynamic identification technique: application to the evaluation of the equivalent strut for infilled frames , 2003 .

[23]  Andreas Stavridis,et al.  Finite-Element Modeling of Nonlinear Behavior of Masonry-Infilled RC Frames , 2010 .

[24]  P. B. Shing,et al.  Recent Results on Masonry Infill Walls , 2010 .

[25]  Tim Schmitz,et al.  Mechanics Of Composite Materials , 2016 .

[26]  김하영,et al.  a in Plane , 2007 .

[27]  L. Cavaleri,et al.  Infilled frames: developments in the evaluation of the stiffening effect of infills , 2003 .

[28]  Richard M. Bennett,et al.  In-Plane Behavior of Structural Clay Tile Infilled Frames , 1999 .

[29]  L. Cavaleri,et al.  Definition of diagonal Poisson’s ratio and elastic modulus for infill masonry walls , 2014 .

[30]  Panagiotis G. Asteris,et al.  Send Orders of Reprints at Reprints@benthamscience.org Numerical Investigation of the Effect of Infill Walls on the Structural Response of Rc Frames , 2022 .

[31]  George C. Manos,et al.  A Nonlinear Numerical Model and its Utilization in Simulating the In-Plane Behaviour of Multi-Story R/C frames with Masonry Infills , 2012 .

[32]  Shuang Li,et al.  An Improved Three-Strut Model for Masonry Infills in RC Frame Structures , 2010 .

[33]  Panagiotis G. Asteris,et al.  On the in-plane properties and capacities of infilled frames , 2012 .

[34]  Bryan Stafford Smith.  Model Test Results of Vertical and Horizontal Loading of Infilled Frames , 1968 .

[35]  Mehmet Baran,et al.  Analytical and experimental studies on infilled RC frames , 2010 .