铝合金轴心受压构件局部稳定与相关稳定性能研究

发布时间：2018-01-04 03:38

本文关键词：铝合金轴心受压构件局部稳定与相关稳定性能研究　出处：《清华大学》2014年硕士论文　论文类型：学位论文

【摘要】：铝合金结构因其特有的优点，在国内外的应用越来越多：铝合金材料能够弥补钢材耐蚀性差的缺点，并且自重轻、低温韧性好、可挤压成型，能够循环利用。但是，铝合金的弹性模量低，仅为普通钢材的三分之一左右，因此，铝合金结构的稳定问题尤为突出。国外对铝合金轴压构件的整体稳定性能已有较系统的研究，目前着重于局部稳定性能，但研究范围不全面，对局部整体相关稳定的研究很少；国内对铝合金的研究刚刚起步，仅针对整体稳定性能，缺少对局部稳定和局部整体相关稳定的研究。因此，针对现有研究成果的不足，本文采用工程中常用的铝合金材料6061-T6和6063-T5，通过大量的试验和数值分析，对大尺寸工形截面铝合金轴心受压构件的局部稳定性能和局部整体相关稳定性能进行研究，，给出板件有效厚度及试件稳定系数的计算公式。本文的主要研究内容如下：（1）对15根铝合金轴心受压短柱的局部稳定性能进行试验研究，包括局部几何初始缺陷、局部屈曲承载力、局部屈曲后极限承载力、破坏形态等。（2）通过有限元软件ANSYS对铝合金轴压短柱的局部稳定性能进行分析，包括398个十字形截面、403个箱形截面和348个工形截面。研究板件厚度、局部几何初始缺陷、整体几何初始缺陷、屈服强度、Ramberg-Osgood模型中应变硬化指数n以及板件间相互作用的影响。提出受压板件有效厚度的简化计算模型，该模型不考虑相邻板件间的相互作用。文中对比了71组现有试验结果，简化计算模型得到的承载力略低于试验结果，偏于安全，能够应用在实际工程中。（3）对12根铝合金轴心受压中长柱的相关稳定性能进行试验研究，得到其局部和整体几何初始缺陷、破坏形态、相关稳定极限承载力等。（4）通过有限元软件ANSYS对铝合金轴压构件的相关稳定性能进行分析，包括673个箱形截面及555个工形截面。研究局部几何初始缺陷、整体几何初始缺陷、屈服强度、Ramberg-Osgood模型中应变硬化指数n的影响。提出铝合金轴压构件稳定系数的计算公式。该公式采用Perry-Robertson公式，在计算构件的相对长细比时，考虑了有效截面的影响。文中对比了现有的试验结果，本文建议公式得到的承载力略低于试验结果，偏于安全，能够应用在实际工程中。本文的研究成果能够在一定程度上填补国内外研究空白，为后续的研究工作提供理论参考，为设计人员提供设计依据，对推广铝合金结构在工程中的应用具有重要意义。
[Abstract]:Aluminum Alloy structure because of its unique advantages, more and more applications at home and abroad: Aluminum Alloy materials can make up for the shortcomings of steel and corrosion resistance, light weight, low temperature toughness, can be extrusion molding, can be recycled. However, the elastic modulus of Aluminum Alloy low, only about 1/3 of ordinary steel, therefore the stability problem, Aluminum Alloy structure is particularly prominent. The foreign study on Aluminum Alloy axial component of overall stability of existing system, the current focus on the local stability, but the scope of the study is not comprehensive, very little research on the local stability of the whole; the domestic research on Aluminum Alloy has just started, only for the overall stability. The lack of local stability and overall stability of the local correlation. Therefore, aiming at the shortage of the existing research results, Aluminum Alloy materials 6061-T6 and 6063-T5 commonly used in the project, through a large number of test The local stability and the overall local correlation stability of aluminum alloy axially loaded members with large section are studied by numerical analysis and numerical analysis. The formulas for calculating effective thickness and stability factor of the specimen are given.
(1) the local stability of 15 aluminum alloy columns under axial compression is studied, including local geometric initial defects, local buckling capacity, local post buckling ultimate bearing capacity and failure modes.
(2) to analyze the local stability properties of short columns of Aluminum Alloy shaft through the finite element software ANSYS, including 398 cross section, 403 box section and 348 I-section. Study on plate thickness, initial geometric defects of local and overall geometric imperfections, yield strength, strain hardening index and n the interaction among plates in the Ramberg-Osgood model. A simplified calculation model of compressive plate effective thickness is proposed, the model does not consider the interaction between adjacent plates. In contrast to the 71 set of existing test results, the simplified calculation model of the bearing capacity is slightly lower than the test results, on the safe side, can be used in practice in the project.
(3) the relative stability performance of 12 aluminum alloy columns under axial compression is experimentally studied. The local and global geometric initial defects, failure modes and relative stability ultimate bearing capacity are obtained.
(4) through the finite element software ANSYS to analyze the related stability of Aluminum Alloy axial compression, including 673 box section and 555 I-section. Study on local geometric imperfections, the initial geometric imperfections, yield strength, strain hardening index n Ramberg-Osgood model. The formula is put forward for calculating the stability coefficient of compression members the Aluminum Alloy axis. The formula by using Perry-Robertson formula in the calculation of component relative slenderness ratio, considering the influence of effective section. This paper compares the existing test results, this paper proposed the formula of bearing capacity is slightly lower than the test results, on the safe side, can be used in practical engineering.
The research results in this paper can fill gaps in research both at home and abroad to a certain extent, provide theoretical reference for subsequent research, provide design basis for designers, and is of great significance for promoting the application of aluminum alloy structures in engineering.

【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU395

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