Advanced Materials Research Vols. 311-313

Abstract: Several rust-transforming reagents based on phosphating technology were studied. The reagents respectively contained potassium ferrocyanide, aromatic oximes (SO) or amide material (GA). By dripping CuSO4 test, linear polarization and polarization curves test, the anti-corrotion performance of phosphate coating were characterized. The results showed that: GA and SO could improve the anti-corrosion performance of phosphate coating. SO restrained the dissolution of metal relying on strong chelation, and the restrained effect of GA depended on durative oxidation and chelation. Comparing to SO, GA could enhance the density of phosphating coating significantly. In addition, the chelation of potassium ferrocyanide had little effect with the anti-corrosion performance.

Abstract: A novel water-compatible hypercrosslinked resin modified by p-aminophenol was synthesized with chloromethylated polystyrene and p-aminophenol by Friedel-Crafts reaction. The objective of this work was to study the adsorption performances for salicylic acid onto p-aminophenol resin. The results showed that the adsorption capacity of salicylic acid onto p-aminophenol resin was superior to XAD-4 resin. It is seen that the maximum adsorption capacity is observed at pH of 3.0. It was found the adsorption dynamics obeyed the pseudo-first-order rate equation and the intra-particle diffusion was the rate-limiting step. The maximum adsorption capacity of salicylic acid for p-aminophenol resin was measured to be 283.7 mg/g with the equilibrium concentration at 404.6mg/L. The micropore structure, the pore diameter of p-aminophenol resin, the hydrogen bond between p-aminophenol resin and salicylic acid bring the larger adsorption capacity.

Abstract: Hot works is an important method for fairing the ship steel plate to improve the quality of shipbuilding, while the mechanical performance of the ship steel plate may be affected during the fairing process, which could result to some safe problems on the structural strength. DH32 high-strength ship steel plate, which is a kind of widely used material in shipbuilding industry, is taken as an object of the present experimental study. Some main parameters of the plate’s mechanical property through hot-works treatment for different times are investigated systematically. Through analyzing the variation of the mechanical properties, some conclusions are drawn and some useful suggestions put forward.

Abstract: Traditional Particle Swarm Optimization (PSO) uses single search strategy and is difficult to balance the global search with local search, and easy to fall into local optimization, a new algorithm which integrates global search with local neighborhood search is presented. The algorithm performs the global search in parallel with the local search by the feedback of the global optimal particle and the information interaction of local neighborhood. Meanwhile, with a new neighborhood topology to control the search space, the algorithm can avoid the local optimization successfully. Tested by four classical functions, the new algorithm performs well on optimization speed, accuracy and success rate.

Abstract: Planar mechanism is the basic structure of mechanical products which are used most widely. The motion of mechanism is based on constraints. In this paper, In this paper, the reason and influence of overconstrains in the planar mechanisms are discussed and defined, and presents the formula for the number of overconstrains in the planar mechanisms.

Abstract: Ti-47Al-2Cr-2Nb-Y alloy pancake were produced by hot-pack forging. The microstructure of as-forged Ti-47Al-2Cr-2Nb-Y alloy were investigated by optical microscopy and scanning electron microscopy, showing that the forged alloy was composed of fine γ grains and retain cast lamella colonies surrounded by elongated B2 phase. Tensile properties of the material showed that yield strength (YS) and ultimate tensile strength (UTS) were decreased from 500MPa and 612MPa at room temperature to 420 MPa and 462 MPa at 800°C, respectively. With the temperature increasing to 900°C, elongation reached 120%.

Abstract: This paper will focus on developing a sort of concrete shrinkage-reducing agents that are generally some surfactants on the basis of some tests. By reference to the main chemical components of some domestic and foreign agents, the following chemicals are initially selecting : tert-butyl alcohol, triethanolamine and polyvinyl alcohol, and then some experiments about these substances were made, including liquid surface tension test, high-strength cement mortar shrinkage test, mortar strength test. Finally, the medicals that can significantly reduce drying shrinkage deformation but have little effect on the strenth of concrete blocks,are selected out as available concrete shrinkage-reducing agents.

Abstract: Based on the total strain crack constitutive model and the available testing data, finite element model on three trusses were established by the finite element procedure MIDAS/FEA and the analysis were executed in order to verify the validity of constitutive model and study the static performance of combined truss. The results show that the finite element model based on total strain crack constitutive can reflect the static performance of combined truss and can carry the affective parameters analysis, which can offer theory evidence for engineering application of combined truss. The failure of three trusses were due to joint failure, however the failure modes were different and changed by the concrete filled in chord. The bearing capacity of three trusses was controlled by the jionts and the strength and stiffness of jionts were increased by the concrete filled in the chord, therefore the bearing capacity of trusses was increased while the deformation was decreased. In combined truss with steel tube and concrete filled steel tube, the concrete-filled steel tube joints can improve the bearing capacity and the steel tube joint can satisfy the requirements of plastic deformation, which have obvious advantages in the engineering application.

Abstract: Finite element analysis on three trusses was carried out in order to study the performance of combined truss with steel tube and concrete filled steel tube. The first specimen was a RHS truss, the second one was a combined truss with steel tube and concrete filled steel tube, and the third one was a concrete-filled steel tube truss. The results show that the finite element model can reflect the static performance of combined truss and can carry out the affective parameters analysis, which can offer theory evidence for engineering application of combined truss. The damage of three trusses was all due to the joint failure and the failure mode was all punishing shearing failure, but the concrete filled changed by the failure place of joints. The bearing capacity of three trusses was controlled by the jionts and the strength and stiffness of jionts were increased by the concrete filled in the chord, therefore the bearing capacity of trusses was increased while the deformation of trusses was decreased. In combined truss with steel tube and concrete filled steel tube, the concrete-filled steel tube joints can improve the bearing capacity and the steel tube joint can satisfy the requirements of deformation, which have obvious advantages in the engineering application.

Abstract: Based on accelerated carbonation test, the variation of the carbonation resistance of ordinary concrete (C40 grade) with early age wet curing time, clinker and CaO content was studied. Results indicate that the carbonation coefficient and the accelerated carbonation depth of the concrete increased obviously with a reduction in the wet curing time at early ages, the clinker or CaO content in binder and the compressive strength at 28 d age. For example, in conditions of curing schedules with 28, 7, 3, 2 and 1 d wet curing at 20 °C with above 95% RH at early ages and then 0, 21, 25, 26 and 27 d air curing at 20 °C with 60% RH, respectively, carbonation coefficients of the concrete incorporated with 15% fly-ash and 25% slag were 1.83, 2.71, 3.61, 4.67 and 5.50 mm/a^0.5 respectively, and thus it can be seen that the calculated times when concrete cover (25 mm) was completely carbonated naturally in now atmosphere (0.04% CO₂) were 191, 104, 52, 31 and 20 years respectively. It is possible to predict the potential carbonation coefficient of the concrete from its clinker or CaO content in binder and from its compressive strength at 28 d age in conditions of the certain wet curing time at early ages.