Flexural Behaviour of Stainless Steel-Concrete-Carbon Steel Circular Concrete-Filled Double Skin Steel Tubes

2014 ◽  
Vol 1065-1069 ◽  
pp. 1345-1348
Author(s):  
Ming Cao ◽  
Rui Wang

In order to improve the traditional concrete filled steel tube's corrosion problems,when it uses as holding column of offshore platforms and as support bar of long-span bridges,this paper mainly studies stainless steel-concrete-carbon steel circular concrete-filled double skin steel tubes's flexural behaviour. Six specimen's tests were carried out.The main parameters varied in the test were the hollow ratio (χ) was 0.45 or 0.69,and shear span ratio (λ) was 1 or 3.The experiment results show how the hollow ratio and shear span ratio effect specimens' ultimate flexural capacity.Also,the experiment results provide experimental basis for structure design.

Author(s):  
Y. L. Chen ◽  
J. R. Bradley

Considerable effort has been directed toward an improved understanding of the production of the strong and stiff ∼ 1-20 μm diameter pyrolytic carbon fibers of the type reported by Koyama and, more recently, by Tibbetts. These macroscopic fibers are produced when pyrolytic carbon filaments (∼ 0.1 μm or less in diameter) are thickened by deposition of carbon during thermal decomposition of hydrocarbon gases. Each such precursor filament normally lengthens in association with an attached catalyst particle. The subject of filamentous carbon formation and much of the work on characterization of the catalyst particles have been reviewed thoroughly by Baker and Harris. However, identification of the catalyst particles remains a problem of continuing interest. The purpose of this work was to characterize the microstructure of the pyrolytic carbon filaments and the catalyst particles formed inside stainless steel and plain carbon steel tubes. For the present study, natural gas (∼; 97 % methane) was passed through type 304 stainless steel and SAE 1020 plain carbon steel tubes at 1240°K.


2022 ◽  
pp. 136943322110651
Author(s):  
Mizan Ahmed ◽  
Qing Quan Liang ◽  
Ahmed Hamoda

Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.


Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 1107-1117
Author(s):  
Li Lai

Abstract In the traditional finite element analysis method, when simulating the feasibility of aseismic structure design of long-span bridges, only finite element analysis is carried out on the bridge structure without considering the aseismic situation of the aseismic structure of the bridge under different schemes, which leads to one-sidedness of the simulation results. Therefore, a new simulation method for the feasibility study of seismic design of long-span bridges is proposed in this paper. 5 seismic isolation schemes for long-span bridge structures are designed. The lock-up devices and liquid viscous dampers are deployed in bridge structure. Numerical simulation of bridge structure is carried out by establishing calculation model and improved hierarchical Kerr spring model. The responses of long-span bridges under seismic loading for 5 seismic isolation schemes are analyzed. On this basis, the seismic performance of long-span bridges is tested by using the multi-point excitation motion equation, the response power spectrum and the structural dynamic reliability analysis based on the first transcendental failure criterion. Experimental results show that all the five seismic isolation schemes are feasible, and the seismic effect of the schemes 4 and 5 is the strongest. The maximum horizontal thrust of pier top is 6.27E+062, 0.50E+07 and 6.00E+06, 2.78E+07, respectively. The proposed method can be used to simulate the seismic response of long-span bridges.


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