A Method of Analysis for Infilled Frames.

Abstract

The behaviour of multi-storey infilled frames is examined for the case of lateral loading. A design method based on an equivalent strut concept is developed to predict the lateral stiffness of the composite frame. It is shown that for the typical case of a non-linear infill material the equivalent strut width is not a constant value but varies with the applied loading and the relative properties of the frame and infill. The lateral strength of an infilled frame is next examined and design graphs are given to enable the cracking and crushing strength of concrete and brickwork infill panels, and also the ultimate shearing strength of brickwork infill panels, to be determined. Finally an example is given showing how the method is applied to full-scale structures and the results compared with those obtained from full-scale tests on a three-storey building. Notation A cross-sectional area d diagonal length of infill E,, E Youne's modulus of infill and frame resoectivelv

FRP Strengthened Brick-Infilled RC Frames: An Approach for their Proper Consideration in Design

“…The contribution of infill walls to lateral stiffness depends on the type of loading and is drastically reduced under reversed cycling loading [7]. In engineering practice, infill walls are usually modelled as a combination of diagonal struts following a macro-modelling approach [8][9][10] without significant loss of accuracy. However, more complex models, such as finite element models with a micromodelling approach, with the use of constitutive relations available in the literature should be implemented to account for the non-linearity of the response of infilled RC frames, the accurate detection of possible failure modes and the verification of simplified models considering the effects of several critical factors, including the width-to-the-height of the infilled frame ratio and friction mechanism at the interface between the frame and the infill [11][12][13][14][15][16][17][18].…”

Seismic Design of Masonry and Reinforced Concrete Infilled Frames: A Comprehensive Overview

“…In the formulas adopted by FEMA 306 and CSA S304.1-04, the strut width for the calculation of in-plane bearing stiffness of infilled frames depends on the ratio of the flexural stiffness of the column to the stiffness of the infill, a factor that was initially suggested by Stafford Smith and Carter (1969) and has been consecutively confirmed by experimental and analytical studies (Papia et al, 2003;Anderson and Brzev, 2009).…”

“…Further investigations by Stafford Smith and Carter (1969) came to the conclusion that it is mainly the flexural stiffness of the column and not of the beam, that influences the stiffness of the infilled frame. They introduced the parameter λ (Equation 6) to express the relative stiffness of the column of the frame to the infill and the parameter α (Equation 7) to describe the length of contact between the infill and the column:…”

“…5) Stafford Smith and Carter (1969) produced curves that related graphically the strut width, w, to the parameter λ (Equation 6) for different panel proportions. In their analysis they assumed the contact zone between the infill and the beam to be constant and equal to half the length of the infill.…”

Comparative Assessment of Strut Models for the Modelling of in-Plane Seismic Response of Infill Walls

“…The diagonal tension strength in [18] is the same as suggested by Saneinejad and Hobbs, where ′ may be taken as 1/20 of the compressive strength in the horizontal direction, 90 ′ . For corner compression failure, a modified version of the method proposed by Stafford-Smith and Carter [20] is suggested (equation 15).…”