焊接管节点结构形式发展及疲劳性能对比  

Development of welded tubular joints and comparison of fatigue behaviour

作　　者：姜磊[1,2] 刘永健 王康宁[1] JIANG Lei;LIU Yongjian;WANG Kangning(School of Highway,Chang'an University,Xi'an 710064,China;Department of Civil Engineering,Queen's University,Kingston KTL 3N6,Canada)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]女王大学土木工程系

出　　处：《建筑结构学报》2019年第3期180-191,共12页Journal of Building Structures

基　　金：国家重点研发计划资助(2016YFC0701202);国家自然科学基金项目(51508027);中央高校基本科研业务费专项资金项目(310821175015)

摘　　要：为研究不同类型焊接管节点疲劳性能差异,梳理焊接管节点结构形式发展和构造创新,总结各类节点热点应力集中系数静力试验和疲劳试验成果,回归分析给出各类节点用于疲劳设计的热点应力幅-循环次数(S_h-N)曲线,并从热点应力幅曲线和热点应力集中系数两方面,对比各类节点疲劳性能差异。结果表明:对于S_h-N曲线,当钢管板厚t≤4 mm时,焊缝缺陷成为影响疲劳强度的主要因素,使得疲劳强度显著降低;现行规范中,CIDECT规范(Design guide No.8)的S_h-N曲线对各类节点设计均偏于危险,DNV-RP-C203的S_h-N曲线可适用于方形鸟嘴式钢管节点和钻石形鸟嘴式钢管节点疲劳设计,但对于其他节点设计偏危险;API RP 2A-WSD中的X’曲线的疲劳强度低于X曲线的,X’曲线适用于鸟嘴式节点和传统的圆形、矩形钢管节点及相应的主管内填混凝土节点设计,X曲线对任何节点设计均偏危险;在相同的几何参数β、2γ和τ(β、2γ、τ分别为支主管宽度比、主管宽厚比及支主管厚度比)下,各类节点的疲劳性能优劣顺序为,圆形钢管混凝土节点、圆形钢管节点、矩形钢管混凝土节点、矩形钢管节点;圆管-矩形钢管混凝土节点疲劳性能略优于矩形钢管节点的疲劳性能,圆管-矩形钢管节点疲劳性能劣于矩形钢管节点的疲劳性能;当β≤0.7时,建议采用方形鸟嘴式钢管节点和钻石形鸟嘴式钢管节点。In order to compare the fatigue behaviour of different types of welded tubular joints, the structural development and innovation on welded tubular joints were introduced and the corresponding statistics on stress concentration factor(SCF) and fatigue life were conducted. The S_h-N curves based on hot spot stress method of different welded tubular joints were developed for practical fatigue design. The comparisons of fatigue behaviour for different welded joints were made based on S_h-N curves and SCFs. The results show that as for S_h-N curves of joints with thickness t≤4 mm, the weld defects become the critical effects, leading to lower fatigue life. In the current design guidelines, the S_h-N curve in CIDECT design guide No.8 is unsafe for all joints. The S_h-N curve in DNV-RP-C203 can be used for square bird-beak SHS joints and diamond bird-beak SHS joints, but it is unsafe for the other joints. In APIRP 2 A-WSD, the so called X’ S_h-N curve is lower than X S_h-N curve. The X’ curve can be applied for bird-beak joints(both square bird-beak SHS joints and diamond bird-beak SHS joints), conventional CHS-CHS, RHS-RHS joints and the corresponding joints with concrete infill in the chords. The X curve is unsafe for all joints. Under the same geometrical parameters β,2γ,τ(where β,2γ,τ are the brace-to-chord width ratio, width-to-wall thickness ratio of the chord and brace-to-chord thickness ratio, respectively), fatigue resistance decreases with following order, CHS-CFCHS joints, CHS-CHS joints, RHS-CFRHS joints, and RHS-RHS joints. The fatigue behaviour of CHS-CFRHS is slightly better than RHS-RHS joints. The fatigue behaviour of CHS-RHS joints is worse than RHS-RHS joints. The square bird-beak SHS joints and diamond bird-beak SHS joints are recommended for practical fatigue design when β≤0.7.

关 键 词：焊接管节点 结构形式发展 疲劳性能 热点应力幅-循环次数曲线 热点应力集中系数 

分 类 号：TU392.302[建筑科学—结构工程]