共查询到19条相似文献,搜索用时 109 毫秒
1.
我国桥梁用钢现状及耐候桥梁钢发展 总被引:1,自引:0,他引:1
我国桥梁用钢强度等级与韧性不断提高,焊接性能持续改善,钢板的适宜厚度逐步提高。铁路桥梁用钢、公路桥梁用钢、跨海大桥用钢成为我国桥梁用钢的主体。顺应时代发展要求的高性能耐候桥梁钢将是我国桥梁用钢发展的主要方向。耐候桥梁钢在我国已经有所应用,但需要系统建立或健全使用耐候桥梁钢的相关国家或行业标准。 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Edward P. Wasserman 《Canadian Metallurgical Quarterly》2002,7(1):1-5
In February 1996 the Tennessee Department of Transportation, in cooperation with the Federal Highway Administration, the American Iron and Steel Institute, the U.S. Navy, and various steel plate manufacturers, agreed to design the first bridge in the United States to use HPS 485W (70W) steel. Since that time the department has constructed a second bridge using HPS 485W (70W) and has let to contract a third bridge that uses HPS 485W (70W) in both quenched and tempered and thermomechanical controlled processing HPS 485W (70W) steel. This paper will discuss lessons learned in the process and present optimization techniques employed. 相似文献
14.
15.
Karl E. Barth Jennifer E. Righman Lora B. Freeman 《Canadian Metallurgical Quarterly》2007,12(3):380-388
This paper details research conducted to determine the applicability of the 2nd and 3rd editions of the AASHTO LRFD Specifications to hybrid I-girders fabricated from high-performance steel (HPS) 690W (100?ksi) flanges and HPS 480W (70?ksi) webs. Specifically, the scope of this paper is to evaluate the applicability of the negative moment capacity prediction equations for noncomposite I-girders subjected to moment gradient. This evaluation is carried out using three-dimensional nonlinear finite-element analysis to determine the ultimate bending capacity of a comprehensive suite of representative hybrid girders. In addition, a design study was conducted to assess the economical feasibility of incorporating HPS 690W (100?ksi) in traditional bridge applications. This was accomplished by designing a series of I-girders with varying ratios of span length to girder depth (L/D ratios) for a representative three-span continuous bridge. Results of this study indicate that both the 2nd and 3rd editions of the specifications may be used to conservatively predict the negative bending capacity of hybrid HPS 690W (100?ksi) girders, however increased accuracy results from use of the 3rd edition of the AASHTO LRFD Specifications. Thus, it is concluded that the restriction placed on girders fabricated from steel with a nominal yield strength greater than 480?MPa (70?ksi) can be safely removed. Additionally, results of the design study demonstrate that significant weight saving can result from the use of hybrid HPS 100W girders in negative bending regions, and that hybrid HPS 690W/HPS 480W girders may be ideally suited to sites with superstructure depth restrictions. 相似文献
16.
Atorod Azizinamini Karl Barth Robert Dexter Camille Rubeiz 《Canadian Metallurgical Quarterly》2004,9(3):212-217
This paper provides a summary of the major research studies conducted or being conducted in the U.S., to address design issues related to use of high performance steel (HPS) in bridge construction. Emphasis of the paper is on the work related to HPS-485W steel, which has specified minimum yield strength of 485 MPa (70 ksi). Design issues that are addressed in this paper include (1) flexural capacity of compact and noncompact HPS sections in negative bending; (2) issues related to ductility of HPS composite girders in the positive sections (this section presents a simplified ductility check for composite plate girders); (3) tensile ductility of HPS plates; (4) shear capacity of the hybrid steel plate girders; (5) live load deflections; and (6) brief overview of the work that is underway to develop innovative bridge configurations capable of incorporating the advantages of HPS. 相似文献
17.
Heat curving is extensively used for fabricating structural steel girders for bridges. Current American Association of State Highway and Transportation Officials (AASHTO) specifications limit usage to Grade 345 steel (Fy = 50?ksi), ruling out Grade 485 (Fy = 70?ksi) high performance steel (HPS). This paper presents results of a three-dimensional finite-element analysis to assess the applicability of existing AASHTO provisions for HPS 485W sections. The finite-element package NASTRAN was used to conduct the analysis and the model calibrated against experimental data obtained from full-scale tests conducted previously by U.S. Steel Corporation. Comparisons include curvatures, lateral deformations, and residual stresses. The calibrated model was used to predict the performance of an identical HPS girder subjected to the same heat/cool cycles. The three-dimensional analysis predicted smaller curvatures as compared with Grade 250 (Fy = 36?ksi) or Grade 345 (Fy = 50?ksi) steel. Comparable curvatures could be obtained by using higher temperatures. 相似文献
18.
Robert J. Dexter William J. Wright John W. Fisher 《Canadian Metallurgical Quarterly》2004,9(3):278-286
This paper presents an overview of materials selection, design, and detailing of steel girders for fatigue and fracture limit states. The historical context of the fracture control plan for bridges is presented. A discussion of fracture toughness of structural steel and weld metal is presented along with typical Charpy and fracture-toughness test data, including the new high-performance steel A709 HPS 485W. Fatigue of cover plate details and distortion-induced cracking are discussed. Methods of dealing with variable-amplitude loading are then compared to test data. 相似文献
19.
In current AASHTO LRFD bridge design specifications, the nominal flexural strength of I-girders made from steel with a yield stress >345 MPa (>50 ksi) is limited to the yield moment rather than the plastic moment and inelastic design procedures are not permitted. With the recent development of high performance steel (HPS) for highway bridges, the need for these restrictions should be revisited. This paper focuses on I-girders made from HPS-100W steel. Two I-girders were designed with HPS-100W steel according to the AASHTO LRFD specifications, neglecting current restrictions related to the use of high strength steels. The I-girders were tested to failure under three-point loading, which simulated the condition of negative flexure at the pier of a continuous-span bridge. The flexural strength and ductility of the HPS-100W I-girders are compared with the strength and ductility anticipated by the AASHTO LRFD specifications for conventional steel I-girders. In addition, the results of relevant previous tests of conventional steel I-girders are summarized and compared with the HPS-100W I-girder test results. 相似文献