In construction stage, a large buffeting response would endanger construction safety and quality for a long span concrete-filled steel tube (CFST) arch bridge. Developing the study on buffeting security is indispensable to CFST arch bridge in construction stage. Combining random vibration analysis of structure with modern probability theory, taking an actual large span CFST arch bridge as example, dynamic reliability of buffeting responses research and analysis is developed, which is based on the buffeting analysis on time domain at the longest cantilever construction stage. The paper gives quantitative valuation on wind-vibration safety performance of the bridge in construction phase and offers a new thought and reference for homologous project.

关键词：钢铁;钢管混凝土管;拱桥;施工阶段

查看摘要 索取原文[8页]

This project addressed the goal of National Strategy for Surface Transportation Research to improve highway structures by enhanced materials, in particular by design and implementation of new, drastically improved steels with respect to strength, low-temperature fracture toughness, weldability, and weatherability. The goal of the project was to develop, standardize and commercialize a family of low-cost, high-performance steels for infrastructure applications. As a result we developed steels with yield strength of 50 to 80 ksi, with Charpy absorbed fracture energy significantly exceeding requirements of bridge construction codes at temperatures down to -100DGF, steels that are easy to weld without pre-heat or post-heat, steels that exhibit best weathering performance among other commercially available steels. In addition these steels are easy to produce; production does not involve any heat treatment or thermo-mechanically controlled processing which is available only to several US Steel companies. The steels developed in this project were commercially produced in the form of plate and wide-flange I-beams. The steels were used for seismic retrofitting of one bridge (in 2000) and for construction of two new bridges (in 2006 and 2010).

关键词：钢材；成本；营销；桥梁；建筑

查看摘要 索取原文[14页]

The thermal performance Rov of Flat-Plate Closed-Loop Pulsating Heat Pipe(FCLPHP) are effected by several elements such as the heat load Q, the tilt angle θ and the filling ratio F, they are interacted each other.In order to predict the effect of Q and θ on the thermal performance at locations Q and θ other than the experimental data conditions, and to study the relationship among the Rov, Q and θ in the range of the experimental data, we need a fitted regression model to estimate the function relationship that describes the data.The postulated depends on the range of the regression variables encountered in the data.In this paper, a simple model was developed.Since the coefficients in the model have been estimated from the experimental data, studies were carried out on an experimental set-up.FC72 was employed as working fluid.Method of least squares was used for building the model.By using the model, effects of the beat load and the tilt angle on the thermal performance of FCLPHP were discussed.It was found that the tilt angle had minimum value in a certain heat load in the experimental range (θ=30°-70°), and it increases with the increase of heat load.A sensitivity analysis was done with the model.

关键词：钢铁；脉动热管；热性能；整体热阻

查看摘要 索取原文[6页]

The goal of the proposed project is to further develop and market advanced 70-ksi-yield strength super-tough steel (designated as NUCu60ST in the text) for use in tank cars transporting cryogenic liquids, like chlorine, for example. Fracture of these tanks resulted in a number of industrial accidents. One in 2005 in Graniteville, South Carolina led to nine deaths and at least 250 injuries. This is a joint project with Union Tank Car Company (UTLX). Developed and investigated at Northwestern University by prior funding from ITI and CCITT, the super-tough cyrogenic steel was included into the 'Next-Generation Rail Tank Car Project', an innovative joint initiative of the three companies (Dow, Union Pacific and UTLX), Association of American Railroads (AAR), and US and Canada Departments of Transportation focused on the design and implementation of a next-generation rail tank car with enhanced ability to safely transport hazardous chemicals.

关键词：钢;坦克车;危险品运输;低温;氯

查看摘要 索取原文[6页]

The construction industry has historically made use of four materials: stone, timber, concrete, and steel. In recent years, civil engineers have been seeking alternative materials to steel and concrete that may be less vulnerable to environmental damage. Rising public concern about traffic delays experienced during construction have increasingly influenced civil engineers to seek materials and methods that allow more rapid construction. At the same time, costs must be competitive with traditional materials because of reduced public sector resources to maintain transportation infrastructure. Fiber-reinforced polymer (FRP) composites have emerged as an attractive potential alternative. Inspections of sign structures by the Florida Department of Transportation (FDOT) have revealed the occurrence of premature corrosion of galvanized steel structural members. As a result, FDOT engineers are also seeking alternative materials that may be employed in these structures.

关键词：建筑材料；石材；木材；混凝土；钢材

查看摘要 索取原文[43页]

In this paper we discuss the standard Jominy curve method, which is used for hardness and microstructure prediction at the core of steel parts of different shapes. It is shown that the simplified method of calculation needs verification by an exact analytical solution of the problem connected with the Jominy end-quench method. For this purpose, an exact analytical method of calculations is proposed. It is established that the cooling rate at the core of steel parts can differ by up to 12as compared with the self-regulated boiling process and extremely forced convection.

关键词：钢铁；显微组织；硬度；顶端淬火曲线；冷却速率

查看摘要 索取原文[16页]

Laser Shot Peening without protective Coating (LPPC) was performed on SS304 austenitic stainless steel using a 300 mJ, 10 ns pulse, 1064 nm wavelength Nd:YAG laser with three different pulse densities. A thin layer of water was used as a confinement layer. The peened specimen was characterised with XRD, AFM and a Profilometer. The stress evaluated at the surface of the laser peened sample shows a maximum compressive stress of 1.6 GPa. The surface roughness and depth profile of microhardness before and after LPPC were investigated.The LPPC region indicate substantial improvement in microhardness and compressive residual stress, with marginal increase of surface roughness.

关键词：钢铁；激光冲击强化；脉冲密度；局限层

查看摘要 索取原文[10页]

Diamond-coated drawing dies are considered as ideal drawing dies for their unique characteristics, such as high hardness, wear resistance and low friction. In order to utilize the superior characteristics of diamond coatings towards improving the drawing performance, the nonlinear FEM simulation is used to simulate the whole low carbon steel tube hollow sinking process, with 2D axi-symmetric elastic-plastic element. Based on the simulation results, the distributions of the axial stress and radial stress are analyzed, the influence of parameters of drawing dies on the diameter shrinkage is investigated. Optimal die parameters are obtained.

关键词：钢铁；金刚石冲模；有限元模拟

查看摘要 索取原文[6页]

关键词：钢铁;射流冲击冷却;膜状沸腾；CFD；VOF；热传系数

查看摘要 索取原文[17页]

To enhance plate quality of cold rolling strip steel, a method based on Ant Colony Optimization with Quantum Action (ACO-QA) is developed. In this method, each ant position is represented by a group of quantum bits, and a new quantum rotation gates are designed to update the position of the ant. In order to makes full efficiency, a pretreatment using fuzzy method is firstly adapted before resolving the mathematical model with ACO-QA. This method overcomes the shortcoming of ACO, which is easy to fall into local optimums and has a slow convergence rate in continuous space.

关键词：钢铁；缺陷识别；冷轧；量子算法；蚁群优化算法

查看摘要 索取原文[9页]