支管在轴向荷载作用下Q460C高强钢T型圆管节点疲劳性能试验研究

发布时间：2018-06-14 05:57

本文选题：高强钢圆管节点 + 热点应力集中系数　；参考：《土木工程学报》2017年04期

【摘要】：对8个支管承受轴向荷载的Q460C高强钢T型圆管相贯节点分别进行热点应力试验和疲劳试验研究,将热点应力试验结果与现有热点应力集中系数计算公式进行对比验证分析,通过疲劳性能试验观察疲劳裂纹的发展过程和疲劳破坏模式,并对比分析了CIDECT和DNV疲劳设计规范中圆管节点疲劳S-N曲线对于高强钢管节点的适用性。研究表明,疲劳裂缝首先出现在67.5°到90°附近应力集中较大的区域(鞍点附近),然后迅速沿着相贯线向冠点处发展,并在裂缝末端产生沿主管轴向的横向裂缝。通过试验结果与已有规范的对比分析表明,CIDECT建议的S-N曲线应用于支管承受轴向荷载的Q460C高强钢圆管节点的疲劳寿命预估在某些情况下是偏于不安全的,而DNV规范的计算值过于保守,因此同样也不适合于Q460C高强钢圆管节点的疲劳性能分析。
[Abstract]:The hot spot stress test and fatigue test of eight Q460C high strength steel T-shaped circular tubular joints subjected to axial load were carried out respectively. The results of hot spot stress test were compared with the existing formulas for calculating the stress concentration factor of hot spots. The fatigue crack development process and fatigue failure mode were observed through fatigue performance tests. The applicability of fatigue S-N curves of circular pipe joints in CIDECT and DNV fatigue design codes for high-strength steel pipe joints was compared and analyzed. The results show that the fatigue crack first appears in the area with large stress concentration (near the saddle point) near 67.5 掳to 90 掳, and then develops rapidly along the intersection line to the crown point, and produces transverse cracks along the supervisor axis at the end of the crack. By comparing the test results with the existing codes, it is shown that the S-N curve suggested by CIDECT is applied to predict the fatigue life of Q460C high strength steel pipe joints subjected to axial load in some cases. The calculated values of DNV code are too conservative, so it is also not suitable for fatigue analysis of Q460C high strength steel pipe joints.
【作者单位】：重庆大学山地城镇建设与新技术教育部重点实验室;重庆大学土木工程学院;中国电建集团成都勘测设计研究院有限公司;
【基金】：国家自然科学基金(51208535) 重庆市自然科学基金(cstc2012jjA30004) 中央高校基本科研业务费(CDJRC11200002)
【分类号】：TU391

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