钢筋混凝土矩形桥墩的地震损伤及其抗震性能分析

发布时间：2018-04-09 23:00

本文选题：钢筋混凝土矩形桥墩　切入点：ABAQUS　出处：《长沙理工大学》2015年硕士论文

【摘要】：随着我国社会经济的迅猛发展和民生经济的日益繁荣,各类大跨度桥梁的建设正如火如荼地进行,而大跨度桥梁的建设往往离不开大量使用钢筋和混凝土。另一方面,我国地震活动频繁,地震往往会导致桥梁生命线的垮塌,延误救援时间,造成极大的生命和财产损失,且钢筋混凝土结构地震易损性较大,因此深入研究钢筋混凝土桥梁结构的抗震、减震理论是非常有必要的。在以往的研究中,人们往往忽略混凝土结构在荷载作用下的损伤累积效应,仅按照结构动力学理论来简化计算,但是,这种简化计算得出的结果并不能反映出结构损伤的真实情况,特别是在结构即将断裂的阶段。倘若我们对结构进行损伤估计、考虑损伤累积效应以及推测结构的剩余抗力,则可以为分析混凝土结构的动力特性、评估桥梁结构的安全性、桥梁抗震设计加固与震后修复技术以及旧桥的维修等提供科学合理的依据。本文详尽地介绍了损伤力学理论基础,通过对混凝土损伤理论及损伤本构方程的分析和总结,归纳出其各自存在的优缺点与局限性。本文的主要研究内容包括下列五点:第一,详细介绍了损伤力学理论的基础知识,分析了混凝土材料的损伤现象及损伤形成机理。同时,为了避开经典损伤理论的缺陷,基于严格的不可逆热力学基础,对损伤演化方程进行了比较详尽的介绍,并总结出一个适用于普遍形式的混凝土损伤模型。第二,制作钢筋混凝土矩形桥墩试件作往复荷载作用下的拟静力试验分析,并从美国PEER数据库中选取部分矩形桥墩数据,整理材料的参数,描述试件的设计细节、试验过程、试验现象等内容,分析了往复荷载作用下的滞回性能和延性性能的影响参数。第三,运用ABAQUS工程分析软件建立钢筋混凝土矩形桥墩模型进行数值模拟。然后编制用户材料子程序UMAT,根据部分实验结果,打靶计算得出模型的损伤参数。第四,采用SPSS 19.0数据分析软件对打靶算得的参数进行非线性回归分析,拟合出一个以轴压比、剪跨比、配箍率、纵筋率为变量来表明设计参数与损伤参数关系的经验表达式。第五,利用拟合的表达式计算一组试件的损伤参数,然后数值模拟计算分析其滞回性能,并与该试件的实验滞回性能对比,评价拟合表达式的合理性。
[Abstract]:With the rapid development of our country's social economy and the increasing prosperity of people's livelihood economy, the construction of all kinds of long-span bridges is in full swing, and the construction of long-span bridges is often inseparable from the use of a large number of steel bars and concrete.On the other hand, the frequent seismic activities in China often lead to the collapse of bridge lifelines, delay the rescue time, cause great loss of life and property, and the earthquake vulnerability of reinforced concrete structures is greater.Therefore, it is necessary to study the earthquake resistance of reinforced concrete bridge structure and the theory of earthquake absorption.In the previous studies, people often ignored the cumulative damage effect of concrete structures under load, and only simplified the calculation according to the theory of structural dynamics, but,The result of this simplified calculation can not reflect the real situation of structural damage, especially in the stage of imminent fracture of the structure.If we estimate the damage of the structure and consider the cumulative damage effect and the residual resistance of the structure, we can analyze the dynamic characteristics of concrete structure and evaluate the safety of the bridge structure.Aseismic design and reinforcement of bridges, post-earthquake repair technology and maintenance of old bridges provide scientific and reasonable basis.In this paper, the theoretical basis of damage mechanics is introduced in detail. Through the analysis and summary of damage theory and damage constitutive equation of concrete, the advantages, disadvantages and limitations of each of them are summarized.The main research contents of this paper are as follows: first, the basic knowledge of damage mechanics theory is introduced in detail, and the damage phenomenon and damage formation mechanism of concrete material are analyzed.At the same time, in order to avoid the defects of the classical damage theory, the damage evolution equation is introduced in detail on the basis of strict irreversible thermodynamics, and a concrete damage model suitable for general form is summarized.Secondly, the quasi-static test analysis of reinforced concrete rectangular pier specimen under reciprocating load is made, and some rectangular pier data are selected from the PEER database of the United States, the parameters of the material are arranged, the design details of the specimen are described, and the test process is described.The influence parameters of hysteresis and ductility under reciprocating load are analyzed.Thirdly, the model of reinforced concrete rectangular pier is established by ABAQUS software.Then the user material subprogram UMATT is compiled and the damage parameters of the model are calculated according to some experimental results.Fourthly, SPSS 19.0 data analysis software is used for nonlinear regression analysis of the parameters calculated by target shooting, and an empirical expression of the relationship between design parameters and damage parameters is obtained by using axial compression ratio, shear span ratio, hoop ratio and longitudinal reinforcement ratio as variables.Fifthly, the damage parameters of a group of specimens are calculated by using the fitted expression, and the hysteretic performance of the sample is analyzed by numerical simulation, and the rationality of the fitting expression is evaluated by comparing the hysteretic performance with the experimental hysteretic performance of the specimen.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55

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