基于应变能的纵肋与横肋连接多轴疲劳评估方法

发布时间：2018-01-01 04:00

本文关键词：基于应变能的纵肋与横肋连接多轴疲劳评估方法　出处：《中国公路学报》2016年12期 　论文类型：期刊论文

【摘要】：为准确评估正交异性钢桥面板结构中纵肋与横肋连接构造的疲劳性能,从疲劳开裂的本质特征出发,以改进的应变能密度为参量,考虑多轴效应对疲劳性能的影响,推导并建立了基于改进的应变能密度疲劳性能评估方法,评估了焊接复杂部位在多轴应力状态下的疲劳性能。在此基础上,针对纵肋与横肋连接部位,以港珠澳大桥正交异性钢桥面板足尺节段模型疲劳试验为研究背景,将模型试验结果与所推导的公式计算结果进行对比,验证提出方法的适用性和准确性。研究结果表明:对于正交异性钢桥面板而言,纵肋与横肋连接构造部位为典型的多轴受力状态,多轴效应对其疲劳性能的影响不可忽略;计算所得单轴应变能密度略小于理论值,只考虑单轴效应对该部位进行疲劳寿命评估会导致偏于不安全的结果;而以总的弹性应变能密度为参量,将导致计算结果偏大,寿命评估结果偏于保守;基于多轴应力的改进能量法计算结果与理论值能较好吻合,且最大相对误差为9.7%;所提方法能适用于正交异性钢桥面板横肋与U肋连接部位疲劳性能评估。
[Abstract]:In order to accurately evaluate the fatigue performance of the orthotropic steel deck structure of longitudinal ribs and transverse rib connecting structure, starting from the essential characteristics of the fatigue cracking, in order to improve the strain energy density parameter, considering the influence of performance of multi axis fatigue effect, establishes an improved evaluation method of fatigue strain energy density is derived and evaluated based on performance. Welding fatigue performance under stress in multi axis complex parts. On this basis, the longitudinal ribs and transverse rib joints, with HZMB orthotropic steel deck full-scale segmental model fatigue test as the research background, the model test and the formula derived by comparing the calculation results and applicability to verify the accuracy of this method. The results show that the orthotropic steel deck, longitudinal ribs and transverse rib connecting structure parts of multi axis stress state of the typical multi axis effect on the fatigue performance Can not be ignored; the calculated uniaxial strain energy density is slightly less than the theoretical value, only consider the effect of uniaxial fatigue life of the site assessment will lead to unsafe results; and to the total elastic strain energy density as parameters will lead to the calculation result is too large, life assessment is more conservative than the results; good agreement with the theoretical value calculated by modified energy method based on multi axial stress, and the maximum relative error is 9.7%; the proposed method can be applied to orthotropic steel deck transverse ribs and U rib connecting parts fatigue performance evaluation.

【作者单位】：西南交通大学土木工程学院;
【基金】：“十二五”国家科技支撑计划项目(2011BAG07B03) 国家自然科学基金项目(51178394,51578455) 中央高校基本科研业务费专项资金项目(2682014CX078)
【分类号】：U441.4
【正文快照】： 0引言正交异性钢桥面板在整体力学性能、适用性、经济性和加工制造特性等方面优点突出,已经成为大跨度桥梁的首选桥面板结构。其性能由结构体系、加工制造条件和服役期外界环境所决定,疲劳问题是制约正交异性钢桥面板应用和发展的重要因素,准确评估疲劳性能是正交异性钢桥面板

【相似文献】