钢筋混凝土损伤对剪力墙受力性能的影响分析

发布时间：2018-01-29 16:54

本文关键词： 材料损伤剪力墙有限元模拟碳化-锈蚀模型　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：在土木工程领域,钢筋混凝土结构凭借其诸多优势仍是当前最普遍的建筑结构形式。在一般大气环境下,基于材料尺度的钢筋混凝土耐久性损伤,最为突出的两方面是钢筋锈蚀和混凝土碳化问题。而一般来讲,混凝土的碳化往往是结构内嵌钢筋锈蚀的前提,而锈蚀往往加速混凝土的碳化,即两者之间存在必然的耦合关系。相对于无损钢筋混凝土结构的研究,对结构在一定服役龄期后综合考虑材料耐久性损伤的结构或构件的力学性能研究往往更具现实意义。本文主要做了如下工作:(1)综合分析钢筋锈蚀和混凝土碳化后受力性能及本构关系,选取出适用于材料损伤钢筋混凝土结构有限元分析的建模本构。碳化混凝土本构上,在未碳化混凝土基础上对碳化混凝土相关参数进行折减;锈蚀钢筋本构关系上,迭代推倒出基于不同钢筋锈蚀率的应力应变本构模型,在模拟中对不同钢筋锈蚀率分别代入相应的应力应变关系。(2)对混凝土碳化、钢筋锈蚀单一方面的预测模型,本文在比较和总结前辈研究的基础上,选定若干参数,建立出西安地区一般大气环境下基于结构服役龄期的简化碳化-锈蚀组合预测模型。给出西安地区在役钢砼结构其混凝土碳化深度及钢筋锈蚀量的组合预测办法,并结合一定的工程检测数据对模型进行验证,具有一定的指导意义。(3)对选定参数的完好剪力墙实现ABAQUS软件的有效模拟的基础上,选取构件服役寿命周期中关键龄期节点,基于不同服役年限,对材料损伤后剪力墙受力性能进行对比研究。研究表明:1 服役龄期未达钢筋开始锈蚀时间前,混凝土的碳化将使结构极限承载力、屈服荷载、整体刚度提高;但相应地,其屈服位移、极限位移及结构延性耗能能力有所降低。2 钢筋的轻微锈蚀将有利于剪力墙结构的延性耗能,当服役龄期至混凝土开始锈胀时,剪力墙各项受力性能劣化加快,此时剪力墙极限荷载、峰值位移、延性系数相对于完好剪力墙降低约40%左右。3 服役龄期继续增长(混凝土锈胀后),钢筋与混凝土之间粘结滑移较快出现,往复荷载下墙体各项性能指标呈快速降低趋势。当剪力墙服役龄期达到内部钢筋锈蚀率为10%左右时(本文剪力墙服役龄期对应103年),剪力墙各项指标降低已超过50%。
[Abstract]:In the field of civil engineering, reinforced concrete structure is still the most common form of building structure by virtue of its many advantages. In general atmospheric environment, reinforced concrete durability damage based on material scale. The two most prominent aspects are the corrosion of reinforcement and the carbonization of concrete. Generally speaking, the carbonization of concrete is often the premise of corrosion of the reinforced bar embedded in the structure, and corrosion often accelerates the carbonization of concrete. That is, there is an inevitable coupling relationship between the two, compared with the study of non-destructive reinforced concrete structure. It is often more practical to study the mechanical properties of structures or members whose durability damage is taken into account after a certain service age. The main work of this paper is as follows: 1). The mechanical behavior and constitutive relation of steel bar corrosion and concrete carbonization are analyzed comprehensively. Based on the constitutive analysis of carbonized concrete, the related parameters of carbonized concrete are reduced on the basis of non-carbonized concrete. In the constitutive relation of corroded steel bar, the stress-strain constitutive model based on different corrosion rate of steel bar is iteratively pushed down. In the simulation, the corresponding stress-strain relation of corrosion rate of steel bar is put into the corresponding stress-strain relation respectively. In this paper, based on the comparison and summary of the previous studies, some parameters are selected for the prediction model of steel bar corrosion in a single aspect. A simplified prediction model of carbonization and corrosion combination based on the age of service of structure in Xi'an region is established. The combined prediction method of carbonation depth and corrosion quantity of steel reinforced concrete structure in Xi'an is given. . And combined with a certain engineering testing data to verify the model, which has a certain guiding significance...) on the basis of the selected parameters of the intact shear wall to achieve the effective simulation of ABAQUS software. Based on different service years, the stress behavior of shear wall after material damage is compared and studied. The results show that the service age of 1 is not up to the beginning of corrosion time of steel bar. The carbonation of concrete will increase the ultimate bearing capacity, yield load and overall stiffness of the structure. However, the yield displacement, ultimate displacement and ductile energy dissipation capacity of the structure are reduced accordingly. 2 the slight corrosion of steel bar will benefit the ductile energy dissipation of the shear wall structure, when the service age is when the concrete begins to rust and swell. The deterioration of shear wall mechanical properties is accelerated, and the ultimate load, peak displacement and ductility coefficient of shear wall are reduced by about 40%. 3 years of service (after the expansion of concrete). The bond-slip between steel bar and concrete appears quickly. Under reciprocating load, the performance index of the wall decreases rapidly. When the service age of the shear wall is about 10%, the service age of the shear wall is 103 years. The shear wall index has been reduced by more than 50.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375

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