Papers by Keyword: Column

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Authors: Jia Chao Zhang, Lei Ming Zhang, Xi La Liu
Abstract: Reinforced concrete (RC) frame with masonry infill walls is a very common structural system in low and medium rise buildings. The infill walls are usually considered as non-structural components in the design or assessment of buildings. However, many damages in earthquakes have shown that the infill walls can significantly change the structural response to seismic action. Consequently the evaluation of the seismic performance of RC frame with masonry infill walls becomes very important, and also turns to be a major challenge for structure engineers. In this paper a beam-and-column (BAC) macro model for walls is proposed to simulate the masonry infill walls in RC frames. In this model, the masonry panel is replaced by an equivalent rigid frame which is made up of some beam-and-column members. The geometric parameters of each member can be determined simply by equivalent stiffness combined with the original dimensions of wall panel. The physical characteristics are described directly by material properties of wall panel under investigation. To validate the rationality of proposed model, a masonry-infilled RC frame under cyclic reversed loading is analyzed by the proposed model. The results, including crack pattern, load versus displacement relation are then compared with the experiment response. Good agreements are found.
Authors: Bao Chu Yu, Hong Bai Gai, Yun Yu Li
Abstract: Steel tube confined concrete structure and FRP-confined concrete structure were researched and widely applied in structure engineering current years. Based on the advantage and disadvantage of the two types of structure, a new type of structure named FRP-steel composite pipe confined concrete is proposed. Moreover, the feasible and advantageous about the application of this new type in structure engineering is stated. The development prospects of this new type of structure are mentioned as well.
Authors: Yu Kun Liu, Y.L. Chen, De Shuai Liu, Pu Liu
Abstract: In order to get a reasonable and effective adaptable structure design solution, fuzzy comprehensive evaluation method was applied to evaluate various schemes synthetically which has adopted the method of data normalization of the grey correlation evaluation method in pre process. Through the integrated calculation, the result of evaluation can be obtained accurately and rapidly from the static and dynamic value of the structures. An example of column of vertical grinding machine improvement design was given to explain the process of evaluation in details. Result of evaluation indicates that this method performs well in operability and practicability and can be used in the practice of product design and development.
Authors: Seung Sik Lee, Soo Ha Chae, Soon Jong Yoon, Sun Kyu Cho
Abstract: The strengths of PFRP thin-walled columns are determined according to the modes of buckling which consist of local mode for short columns, global mode for long columns, and interaction mode between local and global modes for intermediate columns. Unlike the local and global buckling, the buckling strength of interaction mode is not theoretically predictable. Refined theoretical approaches which can account for different elastic properties of each plate component consisting of a PFRP thin-walled member are used. Based on both the analytical buckling loads and the experimentally measured buckling loads from literatures, the accuracies of Ylinen’s equation and modified AISC/LRFD column design equation for isotropic steel columns were compared. From the comparison, it was found that the modified AISC/LRFD column design equation is more suitable for the prediction of the buckling loads of PFRP thin-walled members than Ylinen’s equations.
Authors: Yin Yin Su, Wei Xiao, Yu Bin Jiao, Run Ping Han, Yan Qiang Li
Abstract: Adsorption of copper ion and methylene blue (MB) ion from aqueous solution was performed by natural wheat straw (NWS) and modified wheat straw (MWS) with citric acid (CA) in fixed-bed column. Adsorption behaviors of single system and binary system were compared at same experimental condition. There was higher adsorption capacity of MWS for binding Cu2+ and MB. In the binary system of Cu2+ and MB coexisted in solution, there was competitive adsorption. The adsorption quantity of Cu2+ or MB decreased with MB or Cu2+ existed. NWS and MWS can simultaneously adsorb Cu2+ and MB from mixtures.
Authors: B.S. Kabanov, Victor P. Gomera, V.L. Sokolov, V.P. Fedorov, A.A. Okhotnikov
Abstract: The main obstacle which prevents the rapid spread of Acoustic Emission (AE) testing on refinery structures in Russia is the complexity of this NDT tool. The lack of well- defined methods of data analysis and the huge amount of AE data collected within each test are the major problems. The possibility of mistakes in a period of testing and data analysis leading to erroneous conclusions related to the condition of the structure sometimes negatively affects the image of the AE method. However, the correct application of AE can bring unique opportunities in the inspection of structures in the industry. Some examples of successful applications and the unique possibilities of AE testing are presented in this paper.
Authors: Yao Yao
Abstract: Up till now, the design code for the determination of fire resistance of reinforced concrete (RC) columns is essentially based on tabulated data. Clearly, a more scientific approach based on an understanding of the fundamental behavior of columns in fire is timely andwill be useful to structural engineers. This paper develops a straightforward and rational method to predict the fire resistance of RC columns,which is based on the traditional Rankine approach. The effect of shear bond, if included in the Rankine approach, will yield moreaccurate predictions. Material deterioration at elevated temperature with regard to the strength and stability of columns is also quantified.
Authors: Togay Ozbakkloglu, Butje Alfonsius Louk Fanggi
Abstract: This paper reports on part of an ongoing experimental program at The University of Adelaide on FRP-concrete-steel composite columns. The results from eight FRP-concrete-steel double-skin columns (DSTCs) that were tested under constant axial compression are presented. The key parameters examined included diameter, thickness, and strength of inner steel tube. The results of the experimental study indicate that concrete in a DSTC system is confined effectively by FRP and steel tubes. The results also indicate that increasing the inner steel tube diameter leads to an increase in the ultimate axial strength and strain of DSTCs. No clear influence of the strength of inner steel tube is observed on the ultimate condition of concrete in DSTCs. These results are presented together with a discussion on the influence of the key parameters on the compressive behavior of DSTCs.
Authors: Pei Zhang, Han Zhu, Apostolos Fafitis
Abstract: Energy consumption and CO2 emissions in buildings is becoming an increasingly important issue. Steel is a major building material with high energy cost. In a reinforced concrete (RC) structure, it accounts for the maximum energy consumption. There is a need to quantify the steel amount in RC for various situations so that reduction or optimization in steel usage can be analyzed. In this paper two different calculations (Calculation-I and Calculation-II) are conducted by using two groups of steel in designing beams, columns and plates for a 20000 m2 five-storeyed frame RC structure. In Calculation-I, or Cal-I in abbreviation, the steel used for beams, columns and plates is HRB335, HRB400 and HPB235 respectively. In Calculation-II, or Cal-II in abbreviation, the steel used for beams, columns and plates is HRB400, HRB500 and CRB550 respectively. The strength of steel used in Cal-II is higher than that in Cal-I. The calculation is carried out by following the standardized concrete structural design code, and the steps involved in calculation are given in certain details as seen necessary. The corresponding energy for producing the steel used in beams, columns and plates is also computed and normalized on per square meter basis. The results show that Cal-II saves 101.76 tons of steel than Cal-I, or 5.09kg/m2, which means a saving of about 64.11 t of standard coal or 1.6×102 t CO2 for the whole structure, or 3.2 kg of standard coal or 7.98kg CO2 for per square meter.
Authors: Ping Yu, Qin Zhang, Li Yang, Jin Xin Gong
Abstract: Different confined concrete models and their influences on column lateral load-deformation relations are compared and studied in this paper. The analytical results show that models have remarkable discrepancies on the descending branch of constitutive curves, and these discrepancies are weakened in predicting of column lateral load-defromation curves due to eccentric compression of confined concrete.
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