Applied Mechanics and Materials Vols. 256-259

Abstract: This study presents a simplified analytical method for predicting the ultimate strength of compressed concrete filled square steel tube columns based on the triple shear unified yield criterion. Based on the triple shear unified yield criterion theory solutions of thick tube, the calculation formulas of axial bearing capacity of the concrete-filled square steel tube columns were deduced with considerations of the restriction effects of steel tube and the effects of the intermediate principal stressed. The results show that the intermediate principal stress effect parameter b has influences on the ultimate bearing capacity. The formulas in the paper have significance in exerting material potential and save material.

Abstract: In order to improve the seismic energy dissipation performance of concrete filled square steel tubular (CFST) columns, the structural measure about puting the additional energy dissipation plat at the bottom of the CFST columns where bears more stress, was proposed. Finite element anylsis of 10 CFST columns with different structural measure were performed under the same axial compression, selecting the thickness and height of the energy dissipation plate as parameters. On the basis of finite element anylasis, this paper, which obtained load-displacement curves of each finite element model, analyzed and compared the bearing capacity of each model. The results show that: comparing to the ordinary CFST columns, the columns with energy dissipation plat show better about bearing capacity and seismic performance, the height of the energy dissipation has a significant effect on bearing capacity but the thickness has less impact.

Abstract: The definition of concrete-filled steel tube and structural characteristics are introduced briefly. On the high bearing capacity of concrete-filled steel tube structure，economy and ease of construction are analyzed and summed up. This paper expounds the general situation of the development of concrete-filled steel tube and research progress.

Abstract: Based on the simulated results of joint of SRC beam and RC column (steel reinforced concrete beam and reinforced concrete column) with steel anchor, an analytical research on failure models and shear performance of three types of joints is conducted, which is composed of SRC beam and RC column, of SRC beam and column (steel reinforced concrete beam and column) and of SRC beam and ASC column (steel reinforced concrete beam and angle-steel concrete column). Then the parameters analysis for joint of SRC beam and ASC column is carried out, and the design formula of shear capacity for joint of SRC beam and ASC column is given on account of a great number of calculated and statistic results.

Abstract: In order to reduce the steel consumption for one of the steel structure residence, a kind of effective approach of optimization design to the original design is given. In this paper, steel consumption of H-section steel beams are taken as objective function, which have relatively larger proportions than others. Design variables are the beam height, web thickness, flange width and flange thickness. The strength, stiffness and stability of the steel beam are taken as constraint condition under the relevant Building Code. By using the sequential quadratic programming method, we set up optimization mathematical model for optimizing the steel structure residence, and then obtain the optimal section size of the steel beams. After the structural optimization design, the steel consumption of GL1 was reduced by 8.24%, compared with those of the original design. Relative to the original design, optimized total steel consumption was reduced by 3.29%. The approach proposed in this paper is an effective method for the optimization design of steel structure residence.

Abstract: With the improvement of the level of architectural science and technology and the modern development of the residential industry higher requirement on building materials and environmental protection was brought forward．Based on the static loading experiment of four reinforced concrete floor slabs, two ordinary and two superimposed with connections, the paper studied their loading mechanism and bending performance, such as deformation, cracks, bearing limit and fail characteristics. Finally, proposals for superimposed slabs' design were put forward, popularization and application of new composite wall plate provides realistic basis.

Abstract: In this paper the theoretical model of reinforced concrete frame structure is established to numerically simulate and analyze its overall morphology with the finite element analysis method. The calculation results shows that at the bottom of the structure the stress and deformation is much larger than other parts with the action of constant load, live load and wind load. And with modal analysis and buckling analysis natural frequency and vibration mode are obtained to avoid resonance and predict the buckling load.

Abstract: In order to evaluate the seismic performance of reinforced concrete (RC) frames retrofitted by FRP, the experiment of RC frames retrofitted at joints by FRP was carried out. The enhancement in seismic performance of the retrofitted frames is evaluated in hysteretic performance, bearing capacity, stiffness degradation and energy dissipation. And the strengthening effect of the frame retrofitted by CFRP and C/GFRP was compared in the experiment. The restoring force model of RC frame joints retrofitted with FRP was proposed and ranges of the characteristic parameters were determined. The equation of restoring force model for joints strengthened by C/GFRP was suggested. The result show that seismic performance of RC frame retrofitted by FRP based on joints can be improved remarkably. The restoring force model which proposed can be used in seismic elasto-plastic analysis of RC frame structure retrofitted by FRP and practical engineering seismic retrofitting design by FRP.

Abstract: The objectives of this research were to investigate the structural behavior of slender steel reinforced concrete (Referred to as SRC)composite columns subjected to eccentric axial loading. The test consisted of 10 slender columns, with rectangular section160×180mm, and steel shape I10 encased in concrete. The stirrup spacing was 150 mm; its diameter was 6 mm. The diameter of longitudinal reinforcing bars was 10 mm. Details of the experimental investigations including description of the test columns, failure modes and mechanisms, strain characteristics, and load-deformation responses are discussed. Effects of concrete strength, slenderness of columns, and eccentricity of axial loads on the load-carrying capacity of slender column are then presented. Based on these results, a range of slenderness ratio and eccentric ratio of slender SRC column is proposed.

Abstract: The basic mechanical properties (tensile strength, compressive strength, elastic modulus, Poisson’s ratio) of inorganic polymer concrete were studied by test in this paper, which were compared with the performances of common concrete under same strength. According to the stress-strain full curve test results of inorganic polymer concrete under uniaxial compression, adopted the relational expression by the code for design of concrete structure, the equivalent uniaxial compression constitutive relation for inorganic polymer concrete could be got by correcting relevant parameter. The bearing capacity and deformation calculated by theoretical formula were compared with the test results. All of them are in good conformity.