施工高温作用下CFRP板增强箱梁桥顶板疲劳损伤破坏模式与寿命预测研究

Using carbon fiber reinforced polymer (CFRP) for structure reinforcement is a very effective technique especially in the bridge structures. However, there still exist many problems to be solved for CFRP plates to fatigue damage failure mode, as a new material, to be used in structural flexural reinforcement. Especially, the research is not enough in-depth in the fatigue life prediction research. By making use the analysis model established and taking practical engineering as reference, this paper makes in-depth exploration of the interface stress and stress distribution of CFRP plate reinforced box girder roof under combined action of the gravity load and vehicle load, the interfacial bond failure mechanism is studied, the CFRP plate stripping failure process is analyzed, the debonding load and ultimate bearing capacity is calculated, and comparison of different anchorage schemes is made. Through experiments and theoretical analysis, stripping bearing capacity of CFRP plate reinforced bridge under multi-field effects of high construction temperature and vehicle load is obtained. Besides, crack width of reinforced concrete beams retrained by CFRP plates pasting on the top deck is calculated in this paper, crack-resistance and ductility analysis of CFRP plates reinforced bridge is made, the fatigue life of the bridge is analyzed and predicted. At last, a systematic conclude of the typical problems arisen in CFRP plates reinforced bridges under specific conditions is made in this article. The subject of CFRP plates reinforcing bridge is studied in depth in aspects of theory, experiments and finite element simulation. The research results has practical engineering value and research significance for the bridge structures reinforced by CFRP plates under special conditions.

碳纤维增强聚合物(carbon fiber reinforced polymer,CFRP)用于结构加固特别是桥梁结构加固中是一项十分有效技术。但是CFRP板材作为一种新型材料应用到土木工程结构尤其是增强箱梁桥梁疲劳损伤破坏模式还有很多问题研究和解决，特别是疲劳寿命预测研究目前研究尚不够深入。本文利用建立的分析模型，参考工程实际，通过试验和理论分析获得相继经历施工高温及汽车荷载多场作用下CFRP板增强桥梁剥离承载力，给出高温作用下CFRP板增强桥梁的抗裂性、延性受力性能分析，对高温作用下CFRP板加固箱梁桥顶板疲劳是损伤破坏模式并对其疲劳寿命进行预测与分析。对CFRP板在特殊条件下加固桥梁中出现的典型问题进行系统归纳并总结规律，从理论、试验和有限元模拟各方面对CFRP板加固桥梁这一课题进行深入研究，其研究结果对CFRP板在特殊条件下加固桥梁这一类结构具有实际工程价值和研究意义。

桥梁结构领域迫切需要新颖并且科技含量高的桥梁增强技术, 碳纤维增强聚合物(carbon fiber reinforced polymer ,CFRP) 用于结构加固特别是桥梁结构加固中是一项十分有效技术。与传统加固材料相比，CFRP 有轻质高强、极好的耐腐蚀性能及耐久性, 施工便捷等优点，受到了桥梁工程界的日益重视。虽然CFRP板替代钢板用来增强桥梁结构是一种十分有效的加固方式，但是纤维板材作为一种新型的材料应用到桥梁加固还有很多问题急需解决，只有对不同工作状态桥梁增强试件的疲劳损伤破坏模式进行试验研究及寿命预测才能进一步明确CFRP板对结构增强后性能的影响，以便为桥梁结构增强工程提出有益指导。 . 本课题利用建立的分析模型，参考工程实际，对相继经历沥青摊铺施工高温和汽车荷载作用下CFRP板增强箱梁桥顶板进行疲劳损伤破坏模式与寿命预测研究，在试验的基础上探讨静载和疲劳荷载作用下CFRP板-混凝土界面的粘结滑移损伤破坏模式与寿命预测。较深入探讨了CFRP板增强箱梁桥顶板的界面应力及其应力分布特点，界面的粘结破坏机理，分析CFRP板剥离破坏过程，计算剥离荷载和极限承载力，并对不同锚固方案下进行对比分析。通过试验和理论分析获得相继经历施工高温及汽车荷载多场作用下CFRP板增强桥梁剥离承载力，给出钢筋混凝土梁在外贴CFRP板条约束情况下裂缝宽度分析计算和CFRP板增强桥梁的抗裂性、延性受力性能分析，重点对CFRP板加固箱梁桥顶板疲劳寿命进行预测与分析。对CFRP板在特殊条件下加固桥梁中出现的典型问题进行系统归纳并总结规律，从理论、试验和有限元模拟各方面对CFRP板加固桥梁这一课题进行深入研究，其研究结果对CFRP板在特殊条件下加固桥梁这一类结构具有实际工程价值和研究意义。