权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

A study on development and application of high performance steel for bridge structures

桥梁结构用高性能钢的开发与应用研究

基本信息

批准号：
08305014
负责人：
MIKI Chitoshi
金额：
$ 7.68万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08305014/
关键词：
High performance steel Fracture toughness Brittle fracture Fatigue behavior Low cvcle fatigue Large input heat welding High strength steel 破壊靭性 CTOD 脆化脆性亀裂繰返し塑性歪み破壊じん性隅角部シャルピー試験 CTOD試験

项目摘要

In this research project, the objective is to develop and apply high performance steel for bridge structures. The followings were studied.1) Deterioration of fracture toughness due to large plastic strain: Concerning the cold-worked bending process or huge earthquakes, the deterioration of fracture toughness due to large plastic strain was studied. In addition, the differences of effect between tensile plastic strain and compressive plastic strains were discussed with some kinds of steels by observation of brittle fractured surface and mechanical testing.2) Possibility of large input heat welding: Because of some negative effects, such as cracks or deterioration of properties and so on, generally, it has been prohibited to, apply the large input heat welding. In this research project, concerning the high performance steels, the applicability of large input heat welding was tested with carrying out the CTOD testing of large scale welded girder specimens.3) Fatigue Performance of High Strength Steel: For rationalization of steel bridges, fatigue performance of high strength steels was discussed with joint and large-scale girder specimens. In this study 900 MPa class steel, which has never used for actual bridges, was dealt with. In addition, improvement methods of fatigue strength were also studied.4) Low Cyclic Fatigue Behavior under Earthquake: Concerning the low cycle fatigue failure of steel pier under earthquake, low cyclic fatigue testing was carried out, and damage accumulation mechanism was studied5) Brittle Fracture of Beam-Column Joint: In order to improve the toughness and ductility of steel beam-column joint, cyclic loading testing was carried out and some retrofitting and improving techniques were also tested. In that testing, brittle fracture which initiated from that welded corner could be simulated experimentally. As a result, decreasing the strain concentration at the corner with corner rib was the most effective for prevention of brittle fracture.

在这个研究项目中，目标是开发和应用高性能的桥梁结构钢。研究了以下内容。1)大塑性应变导致断裂韧性下降：针对冷加工弯曲过程或大地震，研究了大塑性应变导致断裂韧性下降的问题。此外，通过脆性断口观察和力学试验，讨论了几种钢的拉伸塑性应变和压缩塑性应变的作用差异。2)大输入热焊的可能性：由于一些负面影响，如裂纹或性能恶化等，一般已禁止应用大输入热焊。本课题针对高性能钢，通过对大型焊接梁试件进行CTOD试验，验证了大输入量热焊接的适用性。3)高强钢的疲劳性能：为使钢桥合理化，采用节点和大型梁试件对高强钢的疲劳性能进行了探讨。在本研究中，处理了从未用于实际桥梁的900mpa级钢。此外，还研究了提高疲劳强度的方法。4)地震作用下的低周疲劳行为：针对地震作用下钢墩的低周疲劳破坏，进行了低周疲劳试验，研究了损伤累积机理。5)梁柱节点脆性断裂：为了提高钢梁柱节点的韧性和延性，进行了循环加载试验，并进行了一些改造和改进技术的试验。在该试验中，从焊接角开始的脆性断裂可以进行实验模拟。结果表明，降低带角肋的转角处的应变浓度是防止脆性断裂最有效的方法。