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Hybrid Reinforced Concrete Frame Building with Pumice Brick Masonry Infill under Static Lateral Loading  [PDF]
Akmaluddin,R. S. Saftaningtyas,S. Rawiana,Z. Gazalba
International Journal of Engineering and Technology , 2012,
Abstract: The purpose of this study is to investigate the behaviour of hybrid reinforced concrete frame with pumice brick masonry infill under static lateral loading. The term hybrid herein is referred to the frame composed of precast block masonry unit and cast in-place reinforced concrete beams. Parameters considered in this study were frame opening representing doors and windows commonly used in the wall system. Six types of frame namely FS, FB, FDE, FDC, FWE and FWC designation for solid frame, bare frame, frame with door opening at edge, frame with door opening at centre, frame with window opening at edge and frame with window opening at centre respectively were considered. Test results indicated that the FS has a maximum lateral strength greater than that of FB. The lateral strength of FS was about 3.68 of FB. The frames with various openings have lateral strength nearly 2.3 of lateral strength of the bare frame, FB. Ductility factor of the frames varied from 2.4 to 4.92. The residual strength of the frame with openings were varies between 2.33 and 3.35 of the bare frame. The stiffness of the infilled frames with opening were varied from 3.56 to 3.67 of the bare frame. The presence of openings in the infilled frame did not affect the frame stiffness considerably.
A Review On Partial Infilled Frames Under Lateral Loads  [PDF]
PM Pradhan,PL Pradhan,RK Maskey
Kathmandu University Journal of Science, Engineering and Technology , 2012, DOI: 10.3126/kuset.v8i1.6054
Abstract: Masonry infilled walls are provided within the reinforced concrete structures without being analyzed as a combination of concrete and brick elements, though in reality they act as a single unit during earthquakes. The performance of such structures during earthquakes has proved to be superior in comparison to the bare frames in terms of stiffness, strength and energy dissipation. There are plenty of researches done so far for infilled frames, however partially infilled frames are still the topic of interest. Though it has been understood that the infills play significant role in enhancing the lateral stiffness of complete structure, the past experience in various earthquakes have proved that the partially infilled framed structures somehow are affected adversely. This paper intends to highlight the need of knowledge on partially infilled frames and the composite action. It also summarizes the findings till date done by various researchers on the behavior of partial infilled frames under lateral loads.
On utilization of seismic resistance of masonry infills in design of lowrise mixed r.c. buildings -A case study  [PDF]
Amiya Kumar Samanta
Journal of Engineering and Applied Sciences , 2009,
Abstract: In early stage of civilization, people constructed mostly masonry buildings based on those low-engineered and empirical approaches. In design of new buildings, the structural behaviour of masonry elements is of interest mostly in case of infilled frames or mixed RC frames, where masonry element are also being utilized as participating in structural behaviour of the building. The infilled frames show larger ductility than isolated masonry walls. Very few codes have made provisions on RC frames with brick masonry infill. Euro code (8) and Nepal Building Code (201) make some provisions for ordinary building up to three storey in the low seismic zones, whereas the Indian seismic code IS: 1893 recommends linear elastic analysis for the bare RC frames excluding the effect of brick infill. In the present case study, the author makes an attempt to evaluate contributions of such infill on RC frames using the literature of Aliaari (2005) and effectively utilizes in design of mixed masonry RC frame structures.
Equivalent Strut Width for Partial Infilled Frames
Journal of Civil Engineering Research , 2012, DOI: 10.5923/j.jce.20120205.03
Abstract: The usual practice in the analysis of reinforced concrete frame structures is to analyze the frames with skeleton members comprising of only slabs, beams and columns. However, in reality the structures also possess masonry infills within most of the frames, but they are ignored in the models so as to minimize the computational works. Researchers have indicated that the frames comprising of masonry panels behave significantly stiffer as compared to bare frames. The infills contribute in stiffening the frames, but researches also show that the partial infills can cause adverse effect known as captive column effect. A lot of experimental evidences show that the captive column effect causes the partially infilled frames to damage during earthquakes. It is still a matter of interest to researchers to find out how much shear actually occurs at the location where the wall terminates. The shear force generated at the points where the wall terminates within the frame in the windward side causes the windward side column to fail. This study is done to identify the shear force values at such locations through analytical formula. The equivalent strut width as provided by various researchers is compared with the established formula for verification and further applied to obtain the shear forces at various locations in partially infilled frame. Equivalent strut width formulation is done in this paper, which may be used directly in the frame analysis wherever partially or fully infilled walls are provided.
不同连接方式下新型砌体填充墙框架结构的抗震性能
Seismic Performance of New Masonry Infilled RC Frame with Different Types of Connections
 [PDF]

吴方伯,李大禹,欧阳靖,,,周绪红
- , 2016,
Abstract: 试验设计了4榀足尺框架结构,其中1榀为空框架,3榀为带新型横孔空心砌块砌体填充墙,带填充墙框架试件分为刚性连接试件和柔性连接试件2种。对各试件在恒定竖向力和水平低周反复荷载作用下的抗震性能进行试验,研究了框架在不同连接形式下的破坏特征、滞回特性、骨架曲线、位移延性、刚度退化、强度退化、耗能能力。结果表明:柔性连接试件抗震性能介于空框架和刚性连接试件之间,框架梁和填充墙采用拉结筋连接试件的抗震性能相对于未设置拉结筋试件有所改善,但提高幅度有限。
Four full-scale reinforced concrete frames, including one bare frame without infilling walls and three infilled frames with the new cross hole hollow block masonry, were tested to study the seismic performance under constant vertical force and horizontal low reversed cyclic loading. The damage behavior, hysteretic characteristics, skeleton curve, displacement ductility, stiffness degradation, strength degradation and energy??dissipating capacity of frames with different types of connections were studied. The results show that the seismic performance of flexible connection specimen is between empty framework and rigid connection specimens, and the seismic performance of the specimen whose frame beam and the infilled wall are connected by tie steel bars has been improved relative to unset specimen, but the increase is limited
Analytical Modeling of Masonry Infilled RC Frames and Verification with Experimental Data  [PDF]
S. Skafida,L. Koutas,S. N. Bousias
Journal of Structures , 2014, DOI: 10.1155/2014/216549
Abstract: The assessment of the response of masonry infilled RC frame structures has been a major challenge over the last decades. While several modeling approaches have been proposed, none can cover all aspects observed in the tests. The present paper introduces a simplified model built on the approach established by Crisafulli and Carr (2007) and addresses its calibration and implementation in a nonlinear analysis software for the evaluation of the in-plane lateral response of infilled RC frames. The proposed model uses a set of elements/springs to account separately for the compressive and shear behavior of masonry. The efficiency of the modeling approach is validated with available experimental data, yielding satisfactory matching. The most intricate issue encountered when attempting to represent a masonry panel is the plethora of the material parameters involved and the lack of complete and available test results. Thus, the numerical investigation is accompanied by a parametric study on the sensitivity of the model to the various parameters to identify the critical modeling quantities and provide guidance on their selection. 1. Introduction The evaluation of the seismic performance of masonry infilled RC frame structures is a widespread problem that has not yet been resolved despite the numerous efforts reported in the literature during the last decades. As a result, and contrary to the finding from the response of masonry infilled structures under actual seismic action, infill is often treated as nonstructural elements and is omitted by the analysis models. Nevertheless, the uncertainty associated with the interaction of the infill with the bounding frame and the different failure modes exhibited, the variability of the material properties, geometrical configurations, and construction methods reveal the complexity of the problem and justify the lack of unified, reliable, and widely accepted approaches for the design and assessment of structural systems that include infill panels. From the computational point of view, the modeling techniques used for the analysis of infilled frames can be divided into two main categories: (i) local or micromodels and (ii) simplified macromodels. The first category is based on the nonlinear finite element method and strives to provide an accurate representation of the frame-infill interaction at the local level. Many of the researchers, who adopted this methodology, for example, Lotfi [2], Lourenco [3], Attard et al. [4], and Mehrabi and Shing [5], used a combination of continuum and interface line elements to simulate the
RC Infilled Frame-RC Plane Frame Interactions for Seismic Resistance  [PDF]
Suyamburaja Arulselvan,K. Subramanian,E.B. Perumal Pillai,A.R. Santhakumar
Journal of Applied Sciences , 2007,
Abstract: Experimental investigation was planned and conducted to study the influence of brick masonry infill in a reinforced cement concrete frame. The analytical methods available needs validation by comparison with experimental results and more accurate methods of analysis like finite element analysis has to be used for the above purpose. In this study, RC frame with middle bay brick infilled representing a five-stories, three bay building in quarter-scale has been taken for experimental investigation and the available methods of theoretical analysis and finite element analysis using ANSYS software for the frames have been carried out. Until the cracks developed in infills, the contribution of the infill to both lateral stiffness and strength was very significant. The change in lateral stiffness, strength, ductility and natural period of the framed structure due to the presence of infills change the behaviour of the building under seismic action. The object of this study was to investigate the behaviour of such infilled frames under seismic loads. For this purpose, five stories, three bay frames with central portion infilled with brick were tested under static cyclic loading simulating seismic action. Analytical works was done to understand the stiffness, strength and behaviour of these types of frames.
Components interaction in timber framed masonry structures subjected to lateral forces  [PDF]
Andreea DUTU,Joao GOMES FERREIRA,Ana Maria GONCALVES,Alexandra COVALEOV
Constructii : Journal of Civil Engineering Research , 2012,
Abstract: Structures with timber framed masonry represent a special typology that is frequently found in Europe and other countries of the world. They are traditional buildings, non-engineered, which showed an unexpected redundancy during earthquakes where reinforced concrete buildings (improperly constructed) collapsed. In the paper, aspects regarding the interaction between timber elements and masonry are mainly addressed, that were observed both in experimental studies, but also in the in situ seismic behavior of this type of structure during important earthquakes.
An Integrated Experimental-Numerical Study of the Performance of Lime-Based Mortars in Masonry Piers Under Eccentric Loading  [PDF]
Václav Ne?erka,Jakub Anto?,Ji?í Lito?,Pavel Tesárek,Jan Zeman
Physics , 2015,
Abstract: Architectural conservation and repair are becoming increasingly important issues in many countries due to numerous prior improper interventions, including the use of inappropriate repair materials over time. As a result, the composition of repair masonry mortars is now being more frequently addressed in mortar research. Just recently, for example, it has become apparent that Portland cement mortars, extensively exploited as repair mortars over the past few decades, are not suitable for repair because of their chemical, physical, mechanical, and aesthetic incompatibilities with original materials. This paper focuses on the performance of various lime-based alternative materials intended for application in repairing historic structures when subjected to mechanical loading. Results of basic material tests indicate that the use of metakaolin as a pozzolanic additive produces mortars with superior strength and sufficiently low shrinkage. Moreover, mortar strength can be further enhanced by the addition of crushed brick fragments, which explains the longevity of Roman concretes rich in pozzolans and aggregates from crushed clay products such as tiles, pottery, or bricks. An integrated experimental-numerical approach was used to identify key mortar parameters influencing the load-bearing capacity of masonry piers subjected to a combination of compression and bending. The simulations indicate increased load-bearing capacities for masonry piers containing metakaolin-rich mortars with crushed brick fragments, as a result of their superior compressive strength.
翼缘削弱型节点空间钢框架在低周反复荷载
Seismic Performance of Reduced Beam Section Connection Steel Frames Under Low-cyclic Loading
 [PDF]

,,孟春辉,,
- , 2016,
Abstract: 为研究翼缘削弱型节点空间钢框架在低周反复荷载作用下的抗震性能,采用有限元分析软件ABAQUS对普通节点和翼缘削弱型节点的空间钢框架模型进行有限元模拟,对2种钢框架模型的破坏形式、承载力、滞回性能、耗能能力、强度及刚度退化性能等进行了对比分析。结果表明:翼缘削弱型节点可使梁端塑性铰外移至梁端翼缘削弱处,避免梁端焊缝处应力集中导致脆性破坏;翼缘削弱型节点等效粘滞阻尼系数与普通节点空间钢框架相比有明显的提高,进入屈服阶段后由于应力重分布,其刚度及承载力退化速度较普通节点空间钢框架慢,翼缘削弱型节点钢框架具有梁铰延性破坏机制,抗震性能较好。
In order to study seismic performance of reduced beam section connection steel frames under low??cyclic loading, finite element simulation analysis of space steel frames with common connections or reduced beam section connections were carried out using ABAQUS software. Based on the finite element simulation analysis results, the failure mode, bearing capacity, hysteretic behavior, energy dissipation capacity, strength and stiffness degradation of the two types of steel frames were compared. The results show that the reduced beam section connection can let the plastic hinge of beam end move outward to beam end flange weakened, and avoid welded connection brittle fracture induced by stress concentration. The equivalent viscous damping ratio of reduced beam section connection steel frame is obviously greater than common connection steel frame. When the steel frames enter the yield stage, the stiffness and bearing capacity degradation of reduced beam section connection steel frame is slower than common connection steel frame. The reduced beam section connection steel frame has beam hinge ductility failure mechanism, and the seismic performance is better
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