6082-T6铝合金轴心受压构件稳定性能研究

发布时间：2018-03-11 01:36

本文选题：6082-T6铝合金　切入点：轴心受压试验　出处：《哈尔滨工业大学》2015年博士论文　论文类型：学位论文

【摘要】：与钢材相比,铝合金材料具有自重轻、耐腐蚀、强度范围广等优点。随着铝合金在土木工程中的应用越来越广,对铝合金结构及构件性能的各种研究工作方兴未艾。由于铝合金弹性模量只有钢材的1/3,其结构和构件的变形和稳定问题更突出。6082-T6是6×××系列铝合金中的较新牌号,与国内常用的传统6061-T6铝合金相比,其强度、耐腐蚀性和焊接性更优良,在土木工程中的应用前景很好。轴心受压是结构构件最基本的受力形式,本文对国产6082-T6铝合金轴心受压构件的稳定性进行了系统的试验和理论研究,为铝合金结构设计和应用提供了参考。本文的主要研究内容和成果如下。进行了117个国产6082-T6铝合金材料试样的拉伸试验,获得并统计了国产6082-T6挤压铝合金的主要力学参数,包括弹性模量E、规定非比例延伸强度f0.2、抗拉强度fu、断裂伸长率At和泊松比v。对比了国产6082-T6铝合金实测应力-应变关系曲线和经典Ramberg-Osgood本构模型,结果表明,国产6082-T6铝合金应力-应变关系曲线基本符合Ramberg-Osgood本构模型。探讨了Ramberg-Osgood本构模型中硬化指数n的不同计算方法。采用快速退火算法进行参数优化,获得曲线整体拟合最优的n值。结果表明,快速退火算法的计算结果比传统两点法的计算结果的离散程度小;在显著性水平α=0.05下,n不拒绝服从正态分布,并获得了n总体均值的置信区间。初始弯曲和初始偏心对轴心受压构件的稳定性影响较大。目前与铝合金挤压型材完整初始弯曲相关的文献很少,本文测量了45根国产6082-T6铝合金挤压圆管和L型截面型材的若干条母线的完整初始弯曲,获得了初弯曲最大值和跨中值。推导了轴心受压构件跨中截面荷载初偏心的计算公式,计算并统计了本文所有73根铝合金试件的跨中初偏心。结果表明,跨中初偏心大于1.8L/1000(L为上下支座转动中心距离)的试件大约占试件总数的10%,参考《铝合金建筑型材第1部分:基材》规定的普通级精度铝合金型材的初弯曲允许值,建议下一次修订规范时适当增大铝合金轴心受压构件的跨中初弯曲代表值,可以考虑采用1.8L/1000。进行了73根国产6082-T6铝合金挤压型材试件的轴心受压试验,包括17根H型截面试件、15根箱型截面试件、15根圆管试件和26根L型截面试件,试件正则化长细比λ?=0.45~3.54,试件两端采用刀口支座模拟铰支,获得了轴压稳定系数和失效模式。试验结果表明:所有H型、箱型和圆管试件均发生绕截面弱轴的弯曲失稳破坏,小长细比的等边L型试件发生弯扭失稳破坏,其余等边L型试件发生弯曲失稳破坏,所有不等边L型试件均发生弯扭失稳破坏。采用有限元分析软件ABAQUS创建了铝合金轴心受压构件的精细化有限元模型,通过与本文试验结果对比,验证了有限元模型预测铝合金轴心受压构件受力性能的可靠性。通过数值计算分析了各种因素(主要包括初始弯曲、初始偏心、材料特性、截面类型和截面尺寸等)对铝合金轴心受压构件整体稳定系数的影响。分析结果表明:初始弯曲、初始偏心、材料特性和截面类型对铝合金轴心受压构件稳定系数都有影响;材料硬化指数n在大于20后对构件轴压稳定系数的影响很小;在不发生局部失稳的条件下,4种截面形式的板件宽厚比和截面高宽比对构件轴压稳定系数都几乎没有影响。研究了铝合金轴心受压构件的设计方法,对比了现行各国规范的轴心受压构件设计柱子曲线和本文试验所得轴压稳定系数。通过批量数值计算,获得了初弯曲分别为L/1000和1.8L/1000时4种截面形式(H型、箱型、圆管和L型)6082-T6铝合金轴心受压构件的整体稳定系数,总计600根杆件,以Perry-Roberson公式作为柱子曲线基本公式形式,对计算结果进行了拟合。对比了本文拟合曲线、各国规范柱子曲线和本文试验结果。结果表明:初弯曲采用L/1000时的拟合曲线与欧洲规范和中国规范的柱子曲线很接近,本文试验值较均衡地分布在中国规范柱子曲线的两侧,初弯曲采用1.8L/1000时的拟合曲线比现行中国规范的柱子曲线更安全,可作为下一次铝合金规范修订的参考。
[Abstract]:Compared with the steel, Aluminum Alloy material has the advantages of light weight, corrosion resistance, strength of a wide range of advantages. With the increasing application of Aluminum Alloy in civil engineering more widely, various research work on the structure and properties of components Aluminum Alloy is just unfolding. The elastic modulus of steel Aluminum Alloy only 1 /3, the deformation and stability of the structure and the component is more prominent in.6082-T6 is a new grade 6 * * * series of Aluminum Alloy, compared with the traditional 6061-T6 Aluminum Alloy commonly used its strength, corrosion resistance and weldability of more excellent application prospect in civil engineering is very good. The axial compression structure is the most basic form of force, this paper the stability of domestic 6082-T6 Aluminum Alloy columns of experimental and theoretical research on the system, which provides a reference for the design and application of Aluminum Alloy structure. The main research contents and results are as follows. The 117 China The tensile test of 6082-T6 producing Aluminum Alloy material samples, and statistics of the main mechanical Aluminum Alloy domestic 6082-T6 extrusion parameters, including elastic modulus E, the specified non proportional extension strength f0.2, tensile strength Fu, elongation of At and Poisson's ratio of V. compared to domestic 6082-T6 Aluminum Alloy measured the stress-strain curve and the classical Ramberg-Osgood the results show that the constitutive model of domestic 6082-T6 Aluminum Alloy stress-strain curves accord with the Ramberg-Osgood constitutive model. The effects of different calculation methods of constitutive model of N hardening index Ramberg-Osgood. The fast annealing algorithm to optimize the parameters, get the optimal value of N curve fitting. The results show that the calculation results of rapid annealing algorithm the results of the two methods than the traditional discrete degree; at significant level a =0.05, n refused to obey the normal distribution, and get the n of the population mean The confidence interval. The initial bend and initial eccentricity on the stability of axial compression members with greater impact. At present Aluminum Alloy extrusion complete initial bending related literature rarely, some bus we measured 45 domestic 6082-T6 Aluminum Alloy extrusion tube and L type profiles complete initial bending, bending and maximum span the value obtained. Calculation formula of axial compression members in cross section of initial eccentricity load calculation, and the statistics of all 73 root Aluminum Alloy test cross in the early eccentric pieces. The results show that the cross in the initial eccentricity is greater than 1.8L/1000 (L is the upper and lower bearing rotation center distance) of the specimen is about the total number of test pieces 10%, reference < Aluminum Alloy Architecture - part first: general level precision Aluminum Alloy > base profiles prescribed by the initial bending allowable value, proposed Specification Revision next time increasing Aluminum Alloy axial compression members span Initial bending can be considered representative of the value of using 1.8L/1000. 73 domestic 6082-T6 Aluminum Alloy extrusion axis compression test specimens, including 17 specimens of H section, 15 box section specimens, 15 pipe specimens and 26 L section specimens, specimen normalized slenderness ratio? =0.45~3.54, specimens of both ends of the knife edge bearing simulation hinge and obtained the axial stability coefficient and failure mode. The experimental results show that all of the H type, box type and tube specimens were lost around the weak cross shaft bending failure, small slenderness ratio of the specimen bending equilateral L type the failure, the rest of the equilateral L type test piece bending failure, all equilateral type L specimens occur bending failure. A refined finite element model by the finite element analysis software ABAQUS to create Aluminum Alloy columns, by comparing with the experimental results, which proves that the finite element model Reliability prediction of mechanical properties of axial compression members by Aluminum Alloy. Through numerical calculation and analysis of various factors (including initial bending, initial eccentricity, material properties, section type and section size) impact on the overall stability coefficient of Aluminum Alloy columns. The results show that initial bending, initial eccentricity, material properties and cross-section types have effects on Aluminum Alloy axial compression stability coefficient; material hardening exponent n is small in 20 after the pressure is greater than the effect of axial stability coefficient; does not occur in the steady condition of the local loss, the 4 section in the form of plate width thickness ratio and section height to width ratio on the axial compression stability coefficient is almost no effect. The design method of Aluminum Alloy columns, compared to the current national standard axial compression column curve and the experimental design of axial compression stability coefficient by batch. Numerical calculation, obtained initial bending are respectively L/1000 and 1.8L/1000 when the 4 section forms (H type, box type, tube type and L) integral stability coefficient Aluminum Alloy axial compression of 6082-T6 components, a total of 600 rods, with Perry-Roberson formula as the basic formula of column curve form, the results of the fitting. This paper compares the fitting curve, all the standard column curves and the experimental results. The results show that the column curves of initial bending curve fitting using L/1000 and European standard and Chinese specification is very close, the test value and both sides are evenly distributed in the Chinese standard column curve, initial bending curve fitting using 1.8L/1000 is more secure than the current standard Chinese column curve, as amended Aluminum Alloy specification of a reference.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG146.21

【相似文献】