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Development of hybrid fiber reinforcements of enhancing structures with integrated performances

开发具有综合性能的增强结构的混合纤维增强材料

基本信息

批准号：
17360201
负责人：
WU Zhishen
金额：
$ 9.54万
依托单位：
Ibaraki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

In this study, first, a comprehensive design concept of hybrid fiber reinforced polymers (FRP) composites with several types of fibers with different specific properties is proposed in order to realize different required performances including tensile strength, stiffness, ductility, creep and fatigue resistances and cost performance as one of the most important indices. Then the material behavior including the long-term performances such as creep and fatigue is experimentally investigated. Quantitative indices to evaluate and control stress or load drops during the gradual fractures of different fibers are proposed and their effectiveness are experimentally verified. The usefulness of adopting continuous fibers with higher energy absorption capacity is also verified.For the application of hybrid fiber sheets in strengthening RC concrete structures, it is found that the use of high modulus carbon fibers in hybrid systems could increase the serviceability such as yielding load. Moreover, … More it is conformed that structures can be strengthened with appropriately designed hybrid fiber reinforcements of consisting of three type of continuous fibers with different specific properties to meet with the overall requirements of structural performances. The debonding failure of hybrid FRP sheets can be also avoided through an appropriate hybrid design. On the other hand, a novel type of FRP-RC hybrid structures as one of new constructions with integrated structural performances is proposed.Then, the flexural or diagonal macro-crack induced debonding failure mechanisms in FRP-strengthened concrete structures are investigated numerically based on nonlinear FEM and fracture mechanics. Moreover, the modeling of long-term behavior such as creep and fatigue of FRP-concrete interface is developed.Finally, a self-sensing manner of FRP-strengthened or FRP-RC hybrid structures is proposed through developing hybrid carbon fiber sensors. Besides, a health monitoring system based on distributed fiber optic sensing techniques is developed to monitor the strengthening effects and other structural performances of FRP-strengthened structures. Less

本研究首先提出了混杂纤维增强聚合物(FRP)复合材料的综合设计概念，以实现不同要求的拉伸强度、刚性、延性、蠕变和疲劳性能，并将性价比作为最重要的指标之一。然后对材料的蠕变、疲劳等长期性能进行了实验研究。提出了评价和控制不同纤维逐渐断裂过程中应力或载荷降的定量指标，并通过实验验证了其有效性。对于混杂纤维布在钢筋混凝土结构加固中的应用，发现高模碳纤维在混杂体系中的应用可以提高结构的屈服荷载等使用性能。此外，…通过合理设计三种不同特性的连续纤维的混杂纤维增强材料，可以对结构进行加固，满足结构性能的总体要求。通过适当的混杂设计，也可以避免混杂FRP片材的剥离破坏。另一方面，提出了一种新型的FRP-RC混合结构，作为一种具有综合结构性能的新型结构形式。然后，基于非线性有限元和断裂力学，对FRP加固混凝土结构的弯曲或斜向宏观裂缝引起的剥离破坏机理进行了数值研究。在此基础上，建立了FRP-混凝土界面徐变、疲劳等长期行为模型，并通过研制碳纤维混杂传感器，提出了FRP加固或FRP-RC混杂结构的自感知方法。此外，还开发了基于分布式光纤传感技术的健康监测系统，用于监测FRP加固结构的加固效果和其他结构性能。较少