频疲劳荷载及高温作用后的混凝土力学特性研

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3.0 赵德峰 2024-11-19 6 4 2.31MB 53 页 15积分

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摘要

混凝土作为目前应用最广泛的建筑材料，以其优越的性能、低廉的价格越来

越受到人们的青睐。但随着高层建筑和公共建筑规模的不断扩大，建筑物发生事

故造成的人员伤亡和经济损失也日趋严重。因此，通过对混凝土力学性能的研究，

掌握更多关于混凝土特性的知识，减少甚至避免损失也显得越发重要。

本文首先指出了在实际工程中，关于混凝土长期处于循环荷载、高温作用等

不利条件下的力学性能问题，越来越受到人们的重视，并概述了国内外学者对该

问题的研究现状及发展方向。本文的主要研究内容：

（1）论述了高频疲劳曲线特性，通过混凝土单轴抗压疲劳试验，运用概率统

计方法，根据混凝土疲劳寿命服从正态分布的两参数威布尔分布的规律，推导出

混凝土对数疲劳方程。

（2）考虑不同温度、不同恒温时间对混凝土的力学性能的影响，进行了混凝

土高温试验研究，分析了不同温度、不同恒温时间对混凝土的抗压强度、弹性模

量和应力-应变关系等力学性能的影响，探讨了高温后混凝土抗压强度、弹性模量

和应力-应变关系随温度和恒温时间的变化规律，并得到了相应公式。

（3）在高温试验基础上，运用有限元分析软件，对高温后混凝土试件进行了

数值模拟计算，进而证明试验数据的可靠性。

关键词：混凝土高频疲劳高温试验有限元分析

ABSTRACT

As the most widely used construction material in China nowadays, concrete is

being used more for its superior performance and low price. Along with the scale of

high-rise building and public building extending continuously, the risk of casualties and

economic losses for the building collapses is also gradually serious. Therefore,

studying of mechanical properties of concrete and acquiring more knowledge of the

properties of concrete to reduce or even avoid the loss become more important.

This article pointed out that the mechanical properties of concrete under adverse

conditions such as a long period of water immersion, cyclic loading, and high

temperature caused more and more attention in the practical engineering. The domestic

and international present research condition and development on the thesis is also

pointed out.

In this article, the following tests were taken to study the mechanical properties of

concrete comprehensively.

(1) The characteristics of the curve of high-frequency fatigue is discussed in this

article. According to a normal distribution of fatigue life of concrete

two-parameter Weibull distribution law, high-frequency fatigue test of

concrete and the method of probability and statistics, concrete fatigue

equation is derived;

(2) The mechanical properties of concrete were studied to analyze the different

temperatures and different holding time on the concrete compressive

strength, elastic modulus and stress - strain relations and other mechanical

properties by compressive strength, modulus of elasticity and constitutive

relation tests of concrete after high-temperature. Compressive strength of

concrete after high temperature, elastic modulus and stress - strain

relationship with temperature and time changes of temperature are

discussed and analyzed, and the corresponding formulas are obtained.

(3) Based on the high-temperature test, finite element analysis software is used

to simulate the concrete specimens and prove the reliability of the

III

experimental data.

Key Words ：concrete, high-frequency fatigue, high-temperature

experiment, finite element analysis

摘要

ABSTRACT

第一章绪论 .....................................................................................................................1

§1.1 本课题的研究背景 ...........................................................................................1

§1.2 国内外研究现状 ...............................................................................................2

§1.2.1 混凝土高频疲劳国内外研究现状 .........................................................2

§1.2.2 混凝土高温作用后力学性能国内外研究现状 .....................................3

§1.3 本文主要研究内容 ...........................................................................................5

第二章混凝土高频疲劳特性试验研究 .........................................................................6

§2.1 引言 ...................................................................................................................6

§2.2 混凝土高频试验及结果 ...................................................................................6

§2.2.1 试件的制作 .............................................................................................6

§2.2.2 实验设备及方案 ......................................................................................7

§2.2.3 疲劳试验及结果 .....................................................................................8

§2.3 疲劳概率分析的基本理论 .............................................................................10

§2.4 本章小结 .........................................................................................................13

第三章混凝土在高温作用后力学性能试验研究 .......................................................14

§3.1 引言 ..................................................................................................................14

§3.2 实验概况 .......................................................................................................14

§3.2.1 试件制作 ................................................................................................15

§3.2.2 试验设备及过程 ....................................................................................15

§3.3 试验结果与分析 ...........................................................................................17

§3.3.1 试验结果 ...............................................................................................17

§3.3.2 试验现象及机理分析 ...........................................................................18

§3.3.3 应力-应变曲线与温度及恒温时间的关系 ......................................... 18

§3.3.4 抗压强度与温度及恒温时间的关系 ...................................................20

§3.3.5 弹性模量与温度及恒温时间的关系 ...................................................23

§3.4 本章小结 .........................................................................................................26

第四章混凝土高温后非线性有限元分析 ...................................................................27

§4.1 引言 .................................................................................................................27

§4.2 有限元法的基本理论 .....................................................................................27

§4.3 混凝土构件模型单元介绍 ...........................................................................29

§4.3.1 SOLID65 单元的线性行为 ...................................................................29

§4.3.2 SOLID65 单元的非线性行为 ...............................................................31

§4.4 高温后混凝土试件的 ANSYS 计算分析 ..................................................... 33

§4.4.1 混凝土试件的建模及基本参数 ...........................................................33

§4.4.2 边界条件及荷载的施加 .......................................................................33

§4.4.3 模型求解及结果分析 ...........................................................................34

§4.5 本章小结 .........................................................................................................41

第五章结论与展望 .......................................................................................................42

§5.1 本文主要工作回顾 .........................................................................................42

§5.2 本文的主要结论 .............................................................................................42

§5.3 问题与展望 .....................................................................................................42

参考文献 .........................................................................................................................44

在读期间公开发表的论文和承担科研项目及取得成果 .............................................48

一、论文 ............................................................................................................48

二、科研项目 ....................................................................................................48

致谢 ........................................................................................................................... XLIX

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摘要：

I摘要混凝土作为目前应用最广泛的建筑材料，以其优越的性能、低廉的价格越来越受到人们的青睐。但随着高层建筑和公共建筑规模的不断扩大，建筑物发生事故造成的人员伤亡和经济损失也日趋严重。因此，通过对混凝土力学性能的研究，掌握更多关于混凝土特性的知识，减少甚至避免损失也显得越发重要。本文首先指出了在实际工程中，关于混凝土长期处于循环荷载、高温作用等不利条件下的力学性能问题，越来越受到人们的重视，并概述了国内外学者对该问题的研究现状及发展方向。本文的主要研究内容：（1）论述了高频疲劳曲线特性，通过混凝土单轴抗压疲劳试验，运用概率统计方法，根据混凝土疲劳寿命服从正态分布的两参数威布尔分布的规律，推导出混凝...

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