货运繁重公路正交异性板钢桥弧形切口的疲劳性能

发布时间：2018-02-10 13:28

本文关键词： 桥梁工程正交异性板钢桥有限元分析弧形切口疲劳车模型　出处：《中国公路学报》2017年03期 　论文类型：期刊论文

【摘要】：为研究货运繁重公路上某正交异性钢桥面弧形切口开裂现象,基于动态称重系统(WIM)得到了疲劳车模型,并建立了钢箱梁节段模型和桥面板子模型,开展了该钢桥弧形切口应力响应分析和疲劳寿命评估。研究表明:横隔板弧形切口的应力局部效应非常明显,其横桥向应力影响线长度在2个纵肋范围左右,纵桥向应力影响线长度在2个横隔板范围左右;弧形切口仅能分辨轴组,而不能分辨轴组内单轴,因而1辆疲劳车加载可以在弧形切口产生2个大应力幅,分别对应中间双联轴和后面的三联轴;弧形切口在最小净截面处存在显著应力集中,周围存在明显的应力梯度,越靠近弧形切口边缘,应力梯度越明显,其最大主应力方向与实桥开裂形态相符;面内应力显著主导弧形切口应力响应,横隔板存在一定的面外变形,适当增加横隔板的厚度,可有效降低弧形切口应力水平;考虑轮载横桥向分布,纵肋R18和R19之间的弧形切口疲劳寿命为6~13年,这与实桥弧形切口疲劳开裂时间和位置均比较吻合;货车通行比例高、通行量大和超载严重是导致该桥过早出现疲劳开裂的主要原因;提出的实测疲劳车模型能为货运繁重公路上的钢桥,特别是正交异性钢桥面板疲劳设计和评价提供重要的参考。
[Abstract]:As an orthotropic steel bridge deck cracking phenomenon of heavy arc incision on the highway freight, dynamic weighing system based on (WIM) the fatigue car model, and a model is established and the bridge deck board girder segment model, carry out the steel arc incision stress response analysis and fatigue life evaluation. The results show that: the diaphragm arc incision local stress effect is very obvious, the transverse stress influence line length in 2 longitudinal range around the longitudinal stress influence line length in the 2 range of diaphragm; arc incision can only distinguish axis group, and cannot distinguish axis within the group of single axis, so the 1 car car fatigue loading can 2 high stress amplitude in the curved incision triple axis corresponding to intermediate shaft and double back arc incision in the smallest; the net section has significant stress concentration, obvious stress gradient around, the more close to the arc cut edge should be The stress gradient is more obvious, the maximum principal stress direction should be consistent with the bridge crack shape; stress significantly dominant arc incision stress response, the diaphragm has certain surface deformation, appropriate increase of diaphragm thickness, can effectively reduce the arc incision stress level; considering the load transverse distribution of curved incision fatigue the life between the longitudinal ribs and R19 R18 for 6~13 years, and the real bridge arc incision fatigue cracking time and location are in good agreement; a high proportion of truck traffic, traffic and a large amount of serious overload is the main cause of premature fatigue cracking of the bridge; the measured fatigue truck model is put forward for heavy freight on the highway bridge in particular, provides an important reference for the orthotropic steel deck fatigue design and evaluation.

【作者单位】：湖南大学土木工程学院;佛山市路桥建设有限公司;
【基金】：国家重点基础研究发展计划(“九七三”计划)项目(2015CB057701) 国家自然科学基金项目(51278191) 湖南省交通科技项目(201522)
【分类号】：U441.4

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