基于性能的FRP加固钢筋混凝土框架抗震设计研究

发布时间：2018-04-26 04:22

本文选题：FRP抗震加固设计 + 数值分析　；参考：《东北大学》2013年博士论文

【摘要】：对既有结构进行抗震加固,是减轻地震灾害、减少人民生命财产损失的有效手段。随着纤维复合材料的发展,采用纤维增强塑料(fiber-reinforced polymer, FRP)对结构构件进行抗震加固引起土木工程人员的广泛关注。然而,针对FRP加固结构而言,目前的抗震设计理论无法对不同地震作用下、不同加固预期目标给予针对性的FRP加固设计；没有评价FRP加固结构抗震性能的标准和准确评估其抗震性能的有效方法。因此,给出一套完整的、适合FRP加固结构的抗震设计理论是非常有必要的。基于性能的结构抗震设计理论是一种新概念的抗震设防理论,其核心思想是依据建筑物的重要程度,使所设计的建筑结构在遭受未来不同地震作用时具有预期的抗震能力和使用功能,该理论有系统评估普通混凝土结构抗震性能的方法,能够准确评估结构的整体抗震性能。本文将基于性能的结构抗震设计思想引入FRP加固设计中,针对FRP加固钢筋混凝土框架开展了相关研究。本文主要内容及结论有以下几个方面：(1)从适用性、经济可修性、安全性三个方面划分了FRP加固柱、梁构件的性能水平。选取位移角作为性能指标,将显著影响位移角的属性因素引入到位移角的量化当中,给出基于性能的FRP加固构件性能水平的指标限值。在节点满足构造要求的情况下,依据FRP加固混凝土构件柱、梁的性能水平,将FRP加固钢筋混凝土框架的性能水平划分为五个等级：正常使用、暂时使用、修复使用、生命安全及防止倒塌。(2)给出适用于FRP混凝土加固构件的塑性铰模型。依据塑性铰的转角变形能力划分其性能水平等级并给出相关表格。通过算例验证了FRP混凝土加固构件塑性铰模型应用于Etabs的可行性。算例结果表明,基于本文给出的塑性铰模型所得到基底剪力、极限变形能力(顶点位移)比采用Etabs默认塑性铰模型均有所提高。相同地震作用下采用本文给出的塑性铰模型所得到的顶点位移和层间位移比默认塑性铰模型均有所减小。(3)给出FRP加固混凝土柱、梁截面屈服前、后刚度以及FRP节点剪切刚度求解公式。依据现有试验结果验证了截面刚度公式的准确性。给出层间侧向刚度与梁、柱、节点刚度的关系式。将目标层间侧向刚度概念引入直接基于位移结构抗震设计中,利用层间侧向刚度计算FRP加固量,可以定量地解决FRP加固混凝土构件的加固量问题。(4)针对FRP加固混凝土框架结构,提出了一种基于能力谱法考虑FRP加固混凝土构件耗能增量的抗震性能评估方法。该方法以FRP构件耗能增量对结构整体等效阻尼比的影响为依据,修正了FRP加固混凝土框架的等效阻尼比。基于该等效阻尼比,能够更加真实的反映FRP加固混凝土框架结构的抗震性能。
[Abstract]:Seismic reinforcement of existing structures is an effective means to reduce earthquake disasters and reduce the loss of people's lives and property. With the development of fiber composite materials, the application of fiber reinforced plastic fiber reinforced polymer (FRPP) to the seismic strengthening of structural members has attracted widespread attention of civil engineers. However, for the FRP reinforced structures, the current seismic design theory can not be targeted to different reinforcement targets of FRP reinforcement design under different earthquake. There is no standard to evaluate the seismic performance of FRP strengthened structures and an effective method to evaluate its seismic performance accurately. Therefore, it is necessary to give a complete set of seismic design theory suitable for FRP reinforced structure. The performance-based seismic design theory of structures is a new concept of seismic fortification theory, whose core idea is based on the importance of buildings. The designed building structure has the expected seismic capacity and function when it is subjected to different earthquake in the future. The theory has a systematic method to evaluate the seismic performance of ordinary concrete structure and can accurately evaluate the overall seismic performance of the structure. In this paper, the performance-based seismic design of structures is introduced into the design of FRP reinforcement, and the relevant research on reinforced concrete frames strengthened by FRP is carried out. The main contents and conclusions of this paper are as follows: 1) the performance level of FRP strengthened columns and beam members is divided from three aspects: applicability, economic repairable and safety. The displacement angle is selected as the performance index, and the attribute factors which affect the displacement angle are introduced into the quantization of the displacement angle, and the index limit of the performance level of the FRP strengthened member based on the performance is given. Under the condition that the joints meet the construction requirements, according to the performance level of FRP reinforced concrete members and beams, the performance level of reinforced concrete frame strengthened by FRP is divided into five levels: normal use, temporary use, repair use. A plastic hinge model for FRP reinforced concrete members is presented. According to the angle deformation ability of plastic hinge, the performance level is classified and the relevant tables are given. The feasibility of applying the plastic hinge model of FRP reinforced concrete member to Etabs is verified by an example. The numerical results show that the ultimate deformation capacity (vertex displacement) based on the plastic hinge model presented in this paper is higher than that of the Etabs default plastic hinge model. Under the same earthquake action, the vertex displacement and the interstory displacement obtained by the plastic hinge model given in this paper are smaller than those of the default plastic hinge model. After stiffness and FRP joint shear stiffness formula. The accuracy of the cross-section stiffness formula is verified by the existing experimental results. The relationship between the lateral stiffness and the stiffness of beams, columns and joints is given. The concept of lateral stiffness of target floors is introduced into the seismic design of displacement-based structures directly, and the reinforcement quantity of FRP can be quantitatively solved by using interstory lateral stiffness to solve the problem of reinforcement quantity of concrete members strengthened by FRP. A method for evaluating seismic performance of concrete members strengthened with FRP based on capacity spectrum method is presented. This method is based on the effect of the energy dissipation increment of FRP members on the overall equivalent damping ratio of the structure, and modifies the equivalent damping ratio of the concrete frame strengthened by FRP. Based on the equivalent damping ratio, the seismic behavior of concrete frame structure strengthened by FRP can be more truly reflected.
【学位授予单位】：东北大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU375.4;TU352.11

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