Papers by Keyword: Column

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.

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.

Abstract: Steel-reinforced concrete (SRC) columns have been widely used over the past few decades. However, very limited research has been conducted on the time-dependent behavior of these columns caused by creep and shrinkage under sustained loading. This paper presents the results of an experimental study of the long-term behavior of short SRC columns under sustained axial loading. Long-term axial deformations due to shrinkage and creep of the concrete were recorded. In analysis of the test results, time analysis of the SRC columns under sustained axial loads using the age-adjusted effective modulus method was proven to be suitable by employing the ACI 209 model for prediction of shrinkage and the CEB-FIP90 model for the prediction of creep.

Abstract: Lots of bulidings had collapsed in Wenchuan big earthquake in 2008, one important reason is that the structure design has been launched only in X or Y axis of the building respectively, which means the oblique direction compression-bending characteristic has not been fully considered in the actual structure design process. In addition, the moment bearing strength in oblique direction is smaller than the moment strength about the principle axis of the column, so the research on bending strength calculation of biaxial/oblique compression-bending RC column is important to improve the aseismic safty of the buildings under actual earthquake effects. In this paper research achievements about bearing capacity calculation of column under oblique compression-bending action are summarized and analyzed. At last the advice for actual application has also been given.

Abstract: A finite element model of an ultra-precision grinding machine that can have high precision and high stiffness is constructed and structural analysis is done with equivalent stiffnesses of linear motion guides by after structural design and the deformation of the grinding machine is obtained. In order to reduce the deformation of the grinding machine that causes bad influence, structural complement is conducted by adding ribs at the lower part of the column. Also, the straightness of the grinding machine is improved by lifting that the base side of the column.

Abstract: In order to study ribbed thin-walled square steel tube recycled concrete eccentric compression column, used the mechanical properties of ANSYS software, conduct the nonlinear numerical simulation. The analysis of the ribbed and ribbed, recycled coarse aggregate replacement ratio and eccentricity, three factors on the eccentric compression column mechanical performance, proved the thin-walled square steel tube that recycled concrete composite column the effectiveness of three-dimensional finite element simulation. The result shows that: when aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axial displacement and displacement to the reduced to 5.77% and 2.33% respectively. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen shaft voltage and bias displacement has been reduced by 6.53% and 4.22%; When the aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the bearing capacity increased by 1.21% and 2.74%. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the ultimate bearing capacity increased by 1.04% and 2.82%.

Abstract: The theory of structural dynamic analysis is put forward firstly. Then the dynamic performance of HMC80 high-speed precision machining center column is analyzed by means of finite element method. The dynamic performance of the column is analyzed using structural dynamic optimization theory and variation analysis with the thickness of wall plate and the inner rib plates as the parameters thirdly. Based on the analysis results, the structure optimization scheme of the column is obtained. The structure optimization scheme is analyzed and the analysis results show that the dynamic performance of the column optimization scheme is improved obviously.

Abstract: The retrofitting technique of externally wrapped by fiber reinforced polymer (FRP) can significantly enhance the deformability or ductility of deficient concrete columns. This paper develops a new advanced ultimate strain model for circular columns confined with FRP jacket based on a most updated and comprehensive test database where more than 800 axial compression test results of FRP confined circular concrete columns were collected newly. This work began with a careful review on some existing ultimate strain models after which an in-depth comparison between models predictions and experimental test results was conducted. The comparisons revealed that more or less defects of the existing models were detected and there existed large errors of their predictions as a much larger amount of columns than that used in the models derivations were evaluated. It is therefore necessary and of significance to refine a new advanced ultimate model in the paper.

Abstract: This paper presents an experimental investigation of aluminum alloy H-type sections subjected to axial compression between two pinned ends. The specimens were fabricated using 6082-T6 heat-treated aluminum alloy. 26 material tensile tests were performed then a test program included 12 column tests which were separated into 6 test series of different geometry and ranged from 990 to 1840 mm in length in order to obtain a column curve. All the observed failure modes for the column tests were overall buckling and the axial capacities were obtained.

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.