A steel-concrete composite structure (1) is described. The steel-concrete composite structure comprises a steel member (2) having an upper surface (5) and a plurality of shear connector elements (6) upstanding from the upper surface and a concrete slab (4) having upper and lower surfaces (7, 8). The slab is supported on its lower surface by the upper surface of the steel member. The slab comprises a plurality of through holes (9) between the upper and lower surfaces, each through hole tapering towards the lower surface so as to form an inverted frustally-shaped seating surface (10). The concrete slab is configured and positioned with respect to the steel member such that at least one shear connector element projects into each through hole. The steel-concrete composite structure comprises a plurality of removable inverted frustoconical plugs (15), each plug having top and bottom surfaces (18, 19; Fig. 6) and an inverted frustoconically-shaped plugging surface (20; Fig. 6). Each plug has at least one through hole (16) between the top and bottom surfaces. At least one plug (15) is seated in a corresponding through hole (9) of the concrete slab. Each plug is configured such that at least one of the least one shear connector elements (6) projecting into the corresponding through hole (9) is received by a corresponding though hole (16) of the plug. The structure also comprises a plurality of fasteners (17, 29), each fastener coupled to a corresponding shear connector element and arranged to discourage removal of a plug (15) from a through hole (9) of the concrete slab.
In this research, the effects of both current and argon gas pressure on the bending properties of welded joints were studied. Using the possible ranges of welding gas pressures and currents, Tungsten inert gas welding (TIG) of stainless steel (304) sheet was used to obtain their influence on the maximum bending force of the (TIG) welded joints. Design of experiment (DOE) ‘version 10' was used to determine the design matrix of experiments depending on the used levels of the input factors. Response surface methodology (RSM) technique was used to obtain an empirical mathematical model for the maximum bending force as a function of welding parameters (Current and Argon gas pressure). Also, the analysis of variance (ANOVA) was used to verif
... Show MoreCorrosion experiments were carried out to investigate the effect of several operating parameters on the corrosion rate and corrosion potential of carbon steel in turbulent flow conditions in the absence and presence of sodium benzoate inhibitor using electrochemical polarization technique. These parameters were rotational velocity (0 - 1.57 m/s), temperature (30oC – 50oC), and time. The effect of these parameters on the corrosion rate and inhibition efficiency were investigated and discussed. It was found that the corrosion rate represented by limiting current increases considerably with increasing velocity and temperature and that it decreased with time due to the formation of corrosion product layer. The corrosion potential shifted t
... Show MoreThe effect of the magnetic abrasive finishing (MAF) method on the temperature rise (TR), and material removal rate (MRR) has been investigated in this paper. Sixteen runs were to determine the optimum temperature in the contact area (between the abrasive powder and surface of workpiece) and the MRR according to Taguchi orthogonal array (OA). Four variable technological parameters (cutting speed, finishing time, working gap, and the current in the inductor) with four levels for each parameter were used, the matrix is known as a L16 (44) OA. The signal to noise ratio (S/N) ratio and analysis of the variance (ANOVA) were utilized to analyze the results using (MINITAB17) to find the optimum condition and identify the significant p
... Show MoreThis work investigates the effect of the gas nitriding process on the surface layer microstructure and mechanical properties for steel 37, tool steel X155CrVMo12-1 and stainless steel 316L. Nitriding was conducted at a temperature of 550 °C for 2 hours during the first stage and at 750 °C for 4 hours during the second stage. SEM and X-ray diffraction tests were performed to evaluate the microstructural features and the major phases formed after surface treatment. SEM and X-ray diffraction tests were performed to assess the microstructural features and the primary phases formed after surface treatment. The new secondary precipitates were identified as γ′-Fe4N, ε (Fe2–3N), and α-Fe, exhibiting an uneven chain-like pattern wit
... Show MoreThe corrosion inhibition effect of a new furan derivative (furan-2-ylmethyl sulfanyl acetic acid furan-2-ylmethylenehydrazide) on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR) and potentiodynamic polarization. The obtained results indicated that the new furan derivative (furan-2-ylmethyl sulfanyl acetic acid furan-2-ylmethylenehydrazide) (FSFD) has a promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. The density functional theory (DFT) study was performed on the new furan derivative (FSFD) at the B3LYP/6-311G (d, p) basis set level to explore the relation between their inhibition efficiency and molecular electro
The effect of applied current on protection of carbon steel in 0.1N NaCl solution (pH=7) was investigated under flow conditions (0-0.262 m/s) for a range of temperatures (35-55°C) using rotating cylinder electrode. Various values of currents were applied to protect steel from corrosion, these were Iapp.=Icorr., Iapp.=2Icorr. and Iapp.=2.4Icorr. under stationary and flow conditions. Corrosion current was measured by weight loss method. The variation of protection potential with time and rotation velocity at various applied currents was assessed. It is found that the corrosion rate of carbon steel increases with rotation velocity and
has unstable trend with temperature. The protection current required varies with temperature and it inc
Abstract
The aim of this paper is to model and optimize the fatigue life and hardness of medium carbon steel CK35 subjected to dynamic buckling. Different ranges of shot peening time (STP) and critical points of slenderness ratio which is between the long and intermediate columns, as input factors, were used to obtain their influences on the fatigue life and hardness, as main responses. Experimental measurements of shot peening time and buckling were taken and analyzed using (DESIGN EXPERT 8) experimental design software which was used for modeling and optimization purposes. Mathematical models of responses were obtained and analyzed by ANOVA variance to verify the adequacy of the models. The resul
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