Behavior of Framed Shearwalls Made of Corrugated Steel under Lateral Load Reversals

2000 ◽  
Vol 3 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Y.L. Mo ◽  
S.F. Perng

Reinforced concrete buildings with shearwalls are very efficient to resist earthquake disturbances. In general, reinforced concrete frames are governed by flexure and low-rise shearwalls are governed by shear. If a structure includes both frames and shearwalls, it is generally governed by shearwalls. However, the ductility of ordinary reinforced concrete framed shearwalls is very limited. The experiments on framed shearwalls made of corrugated steel was recently reported. It was found that the ductility of framed shearwalls can be greatly improved if the thickness of the corrugated steel wall is appropriate to the surrounding reinforced concrete frame. If the thickness of the corrugated steel wall is too large when compared to the surrounding frame, the ductility will be reduced. It is shown in this paper that the fiber-reinforced plastic composites can be used to strengthen the critical regions of the reinforced concrete frames, so that the seismic behavior (including ductility and energy dissipation capability) is greatly improved.

Author(s):  
Sergiu-Gheorghe Țere ◽  
Bogdan Hegheș ◽  
Horea Constantinescu

It is well-known that for single-storey steel structures, the framework is greatly strengthened and stiffened following the attachment of the roof, floors and walls. The panels in the roofing, flooring and side cladding are also known as “shear diaphragms” by virtue of their resistance to being deformed into parallelograms. This has been verified by on-site practical experience of many structures and design provisions are available for structural engineers. Despite the fact that for single-storey structures, the corrugated steel sheets are the standard elements in constructing the envelopes, in what concerns the reinforced concrete frames there are no guidelines nor recommendations on how to consider the diaphragm effect in structural analysis. In order to better understand the interaction between the corrugated steel sheets and the reinforced concrete frame, a real precast reinforced concrete frame structure was built for experimental testing. The aim of the experimental test is to study the diaphragm effect for reinforced concrete structures and based on the results to identify the discrepancies identified compared to steel structures. The investigation attempts to provide a starting point for future research on the stressed skin design acting on reinforced concrete frames. At the end of the article conclusions are drawn based on the experience obtained during the experimental test.


2014 ◽  
Vol 2014 ◽  
pp. 1-20
Author(s):  
Keyvan Ramin

The introduction of an eccentricity in this system results in a geometric nonlinearity behavior. The midpoint of the diagonal member is connected to the corner joint using a brace member with a relatively low stiffness, thus forming a three-member bracing system in each braced panel. An iterative method of analysis has been developed to study the nonlinear load-deflection behavior of ODBS. The results indicate that the load-deflection behavior of this system follows a nonlinear stiffness-hardening pattern with two yielding points, which reflect the tensile failure of different bracings; the present study aims to investigate the efficiency of applying off-diagonal steel braces to reinforced concrete frames. To achieve this, three types of 2-story, 6-story, and 15-story structures without and with X-bracing and off-center bracing systems were modeled using SAP2000 software, and for micromodeling ANSYS software was used to achieve finite element results for an exact comparison between various retrofitting systems. The results showed that the structures strengthened by toggle bracing system revealed better behavior for low oscillation periods. Moreover, this type of bracing system is quite suitable for 10-story structures but not for higher ones. Its main problem, which requires special contrivances to solve, is the existence of a soft ground floor.


2005 ◽  
Vol 32 (4) ◽  
pp. 283-317
Author(s):  
Dusan Kovacevic

Objective of the presented research is the formulation of one enough sophisticated and, for engineering practice, convenient finite element method (FEM) based numerical model for reinforced concrete frames loaded by seismic actions. For modeling of concrete and steel nonlinear behavior uniaxial constitutive rules are applied. The proposal for inclusion the frame joint deterioration, as well as, interaction of shear and flexural forces (inclined cracks effects), in this model, is given additionally. The results of few numerical tests (linear/nonlinear analysis of reinforced concrete frame loaded by three seismic actions) are given as an illustration of presented theoretical research.


1983 ◽  
Vol 73 (5) ◽  
pp. 1435-1450
Author(s):  
Andrzej S. Nowak ◽  
Elizabeth L. M. Rose

Abstract This paper deals with the evaluation of seismic risk for commercial buildings in Memphis, Tennessee. The seismicity of the area is summarized, and commercial buildings are divided into categories with regard to parameters such as number of stories, year of construction, assessed value, total floor area, and structural type. The distributions of these parameters are presented in the figures. During the study, over 15 buildings were examined on site by a team of experts to evaluate their seismic resistances. The quality of the design, materials, and construction was found to be surprisingly good, particularly in those structures built since 1900. Seismic resistance is analytically evaluated for five buildings: a four-story reinforced concrete frame; a four-story steel structure with vertical trusses; a 13-story stell frame; and two multi-story reinforced concrete frames. The loadings from four sources are considered: EI Centro and Taft earthquakes in California (1940 and 1952, respectively) and the forces specified in the 1979 UBC and 1981 BOCA codes. Ratios of load to capacity are calculated. For each building considered, the expected percentage of damage is evaluated for the two earthquakes. The damage prediction is extended to all commercial buildings in Memphis.


2013 ◽  
Vol 353-356 ◽  
pp. 2357-2361
Author(s):  
Yong Jun Liu ◽  
Yang Yang Liu ◽  
Ran Bi ◽  
Jing Hai Zhou

In general, reinforced concrete frames have excellent fire resistance properties, but more and more concrete buildings collapsed in fires. The majority of past research work on the response of concrete building to fire has looked at the effects of fire upon individual structural members, and most commonly when subjected to heating from standard fire tests. At present, the fire behaviors of whole reinforced concrete frame are not adequately understood. There is a great need for development of models which consider the effects of fire on the whole structure under more realistic heating regimes. There is also a fundamental requirement for further large-scale testing of concrete structures, to observe the behavior of whole concrete structures in real fires and also for validation of advanced computer analysis tools. Accuracy and efficiency are two major concerns in finite element analysis of structural response of concrete frames in fires. In this paper, a multi-type finite elements hybrid model for simulating structural behavior of whole reinforced concrete frames in real fire is suggested.


2016 ◽  
Vol 20 (7) ◽  
pp. 1125-1138 ◽  
Author(s):  
Jing Yu ◽  
Xiaojun Liu ◽  
Xingwen Liang

A new model that can simulate the behavior of construction joint subjected to seismic forces was proposed. Nonlinear time-history analysis was carried out for reinforced concrete regular frame structures designed in different seismic intensity regions as well as with different height-to-width ratios. Two kinds of numerical models are adopted to simulate the seismic behavior of each frame, one with construction joint using the new proposed model and the other without construction joint using the conventional model. Results show that the influence of construction joint on the seismic behavior of reinforced concrete frame is strongly related to structural nonlinearity. It may increase the top displacement and the inter-story drift, change the inter-story drift distributions, and exacerbated the local reaction of key members. The influence of construction joint cannot be ignored for structures with low emergency capacity against major earthquake. Seismic design suggestions are proposed from the aspect of calculation analysis method.


2012 ◽  
Vol 157-158 ◽  
pp. 1173-1177
Author(s):  
Li Xiao ◽  
Wen Zhong Qu ◽  
Jian Gang Wang

Terrorist bombing attacks will endanger and may even destroy the target building structures, resulting in economic loss and casualties. Typical columns and floor slab systems are not designed to resist the complex blast loading. So, in recent years, the effects of blast on conventional public buildings are focused on. In this paper,a two-bay,one-story reinforced concrete frame structure which is used to model a portion of a typical reinforced concrete frame structural system is used to investigate the blast response. The experiments are conducted on two models, allowing a variation in explosives standoff and explosives charge. In each experiment,the blast pressure values are recorded and the degree of damage of the frames are studied. According to the two kinds of experiments, two numerical models are established. ALE method which considers the interaction of the explosive, the air, and the structure is applied.Structure response analyses are performed using the large deformation finite-element computer code, LS-DYNA. The numerical results are compared with the experiment results, and a good agreement is obtained. The calculating results also demonstrate that some experimental value is unreasonable.


2018 ◽  
Vol 149 ◽  
pp. 02062
Author(s):  
Jalal Kettar ◽  
Khadija Baba ◽  
Abderrahman Nounah ◽  
Lahcen Bahi

Masonry is often used in the most of reinforced concrete structure constructions as a filling material that is important on structural characteristics. Structural contribution in the calculations was neglected or misunderstood, mainly due to the lack of a practical calculation methods and an appropriate regulatory tool. The analysis of frames filled with masonry is very complex. This complexity is linked from one part to the difference in the nature of elements and its behavior that make up the masonry itself (brick and mortar) and their interaction, and on the other part, for the large dispersion that characterizes the bricks as well as the execution's quality parameters which make it difficult to define reliable criteria for the masonry. The objective of this work is to experimentally highlight the influence of the hollow brick masonry filler, commonly used in Morocco, on reinforced concrete frames subject to lateral stresses, to deepen understanding the seismic behavior of the masonry structures by evaluating the structural performance of a specimen wall. These experimental results will be compared to those found by modeling prototypes, using SAP 2000 software, based on various approaches and models as well as other results deduced from the other researchers. The experimental study was carried out according to standard NF EN 1052-3 on two reinforced concrete frames, of dimensions (2m X 1.6m), the one with the masonry filling, and the other without filling in order to determine the initial characteristic resistance to the shearing of the masonry walls. The obtained results showed that a filling has a beneficial effect on rigidity which can be doubled compared to an empty frame. in the same way the lateral resistance. But this effect is much contrasted; it depends a lot on the characteristics essentially of the materials (bricks and concrete). This is the main reason, which justifies the divergence of the results deduced from the nine models that we used.


Sign in / Sign up

Export Citation Format

Share Document