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卷边翼缘工形截面构件在轴心压力作用下的稳定承载力研究 总被引:4,自引:2,他引:2
与普通工形截面比较,卷边工形截面构件由于卷边的存在增强了翼缘的抗压屈曲能力,进而提高了截面的承载效率,是一种新型的薄壁截面构件。采用大挠度弹塑性板壳有限元分析方珐,对卷边工形构件在轴心压力作用下的稳定承载性能进行了研究。在考虑构件与板件几何初始缺陷和截面残余应力的情况下,研究了卷边工形截面参数(截面宽高比、腹板高厚比、翼缘宽厚比)与构件长细比的变化对轴心压力构件稳定承载性能的影响。最后,在大量数值分析结果的基础上,归纳总结出了卷边工形构件在轴向压力作用下的稳定承载力设计公式。 相似文献
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基于大挠度弹塑性板壳有限元分析方法,系统地研究了卷边工形梁在两端等弯矩作用下的失稳机理与稳定承载力,揭示了卷边工形截面构件的局部屈曲、畸变屈曲、整体侧向失稳以及它们之间的相互作用。系统地分析了截面宽高比、腹板高厚比、翼缘宽厚比、长细比等构件参数对侧向稳定承载力的影响,并基于大量的数值计算数据给出了卷边工形梁在两端等弯矩作用下的稳定承载力设计公式,可为规范修订以及工程设计提供依据。 相似文献
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为研究腹板加劲卷边槽钢拼合构件的承载性能,分别对由复杂卷边槽钢、腹板?形加劲复杂卷边槽钢和腹板V形加劲复杂卷边槽钢拼合而成的共计30根双肢拼合工字形截面简支受压试件进行了受压试验,其中轴压试件18根,偏压试件12根。研究了腹板加劲对拼合工字形截面构件承载力和失稳模式的影响。试验结果表明:腹板?形加劲槽钢能够有效减小腹板宽厚比,提高拼合截面构件的承载力;腹板加劲使畸变屈曲代替局部屈曲成为构件的主要失稳模式。研究采用有限元软件ANSYS对试件进行建模与受力分析,验证了所提出的有限元模型的准确性。通过有限元变参数分析,分析了构件长细比和偏心距对拼合截面构件承载力的影响。结果表明:轴压状态下与相同用钢量的腹板非加劲构件相比,?形腹板加劲复杂卷边槽钢双肢拼合短柱、中长柱和长柱承载力分别提高20.3%、16.0%和4.4%;腹板V形加劲复杂卷边槽钢双肢拼合短柱、中长柱和长柱承载力分别提高17.4%、8.9%和2.2%;随试件长度的增加,整体屈曲作用更为突出;随着偏心距的增大,整体弯曲屈曲逐渐起主要控制作用,3种截面构件的偏压承载力差距逐渐缩小。 相似文献
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为研究激光焊接奥氏体不锈钢工字形截面轴心受压中长柱的承载性能,对10根激光焊接不锈钢工字形薄柔截面中长柱进行轴心受压试验研究,结果表明,中长柱的破坏模式均为板件局部屈曲与构件整体弯曲屈曲的相关失稳。同时,基于残余应力试验,验证了已有激光焊接不锈钢工字形截面的残余应力分布模型。基于试验结果验证了有限元模型,对激光焊接不锈钢工字形截面轴心受压中长柱开展参数分析,研究了几何初始缺陷和残余应力对中长柱稳定承载力的影响,结果表明,残余应力是影响中长柱稳定承载力的主要因素。结合试验和有限元计算结果,对CECS 410:2015《不锈钢结构技术规程》中轴心受压构件稳定承载力设计公式的适用性进行评估,并考虑残余应力的影响修正了轴心受压构件整体稳定设计公式的计算系数。采用修正后计算系数的规范公式能准确计算激光焊接不锈钢工字形截面轴心受压构件的稳定承载力。 相似文献
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通过12根腹板开孔复杂卷边槽钢和Σ形复杂卷边槽钢双肢拼合工字形简支轴压构件的轴压试验,研究了构件承载能力、失稳模式和拼合作用。采用有限元软件ANSYS对试验进行了模拟,验证了分析模型准确性。并通过有限元变参数分析研究了孔高、孔宽和孔间距对拼合构件承载力的影响。结果表明:复杂卷边槽钢截面双肢拼合开孔构件的腹板多波失稳现象明显,屈曲发生时两腹板间的相互支撑作用较强;Σ形复杂卷边槽钢截面双肢拼合开孔构件能有效地控制腹板局部屈曲的发生并显著提高短柱、中长柱的承载力;设置腹板加劲肋有助于提高孔洞周围板件变形的约束作用,同时也减弱了两单肢腹板间的相互支撑作用;相同条件下,Σ形复杂卷边槽钢截面双肢拼合开孔构件的轴压承载效率与复杂卷边槽钢截面双肢拼合开孔构件相比,短柱提高了32%,中长柱提高了10%,长柱提高了2%;非加劲截面构件在不同长度下,孔高为腹板高度1/2(69 mm)时构件的稳定承载力较孔高为25 mm时下降约7%;而孔宽、孔间距对上述两类截面构件稳定承载力影响不大;此外,采用直接强度法预测非加劲截面双肢拼合构件的承载力结果偏于保守,而对加劲截面双肢拼合构件则略显不安全。 相似文献
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基于部分加劲板件的畸变屈曲和局部屈曲的稳定系数比较,提出了冷弯薄壁型钢卷边槽形截面构件畸变屈曲发生于局部屈曲之后或畸变屈曲不发生的临界控制条件;给出了通过构件畸变屈曲计算长度控制畸变屈曲的临界条件;提出一种控制畸变屈曲的构造措施,即在卷边间加设缀板,并通过已有试验对其有效性进行验证,同时推导了卷边间缀板的刚度需求。结果表明:通过构件截面尺寸控制畸变屈曲不发生或发生在局部屈曲之后,可以不考虑构件畸变屈曲的影响,简化冷弯薄壁型钢卷边槽形截面构件承载力的计算;计算长度小于畸变屈曲半波长一半的构件不发生畸变屈曲;通过在卷边间加设缀板的构造措施能有效阻止部分加劲板件的转动,构件的畸变屈曲荷载和承载力都有很大的提高,缀板布置间距不同,构件承载力的提高幅度也不同,缀板间距越小,构件承载力提高幅度越大。算例分析表明,满足一定间距和刚度需求的缀板能够提高构件的畸变屈曲承载力或避免畸变屈曲的发生。 相似文献
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冷弯薄壁型钢构件的直接强度设计法 总被引:11,自引:0,他引:11
受压或受弯的冷弯薄壁卷边槽钢有板件局部屈曲,截面畸变屈曲和整体弯曲屈曲或弯扭屈曲三种模式。本文着重介绍板件的相关屈曲和计算截面畸变屈曲应力的方法并阐述了三种屈曲模式之间的相关关系。指出用传统的有效截面设计法计算受压和受弯冷弯薄壁卷边槽钢承载力的弊端,较详细地说明了用构件全截面计算的直接强度设计法。 相似文献
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《The IES Journal Part A: Civil & Structural Engineering》2013,6(2):79-88
In this article, the prediction of free vibration characteristics of various initially compressively loaded structural members is given in the form of a master formula. These structural members are optimised for the strength criteria and are subjected to high initial compressive loads (or stresses). These initial compressive loads have to be considered when the free vibration characteristics are evaluated. The standard method is to solve the differential equation considering the term corresponding to these loads. Though this is possible for simple structural members, it is often difficult while dealing with complex structural members with complicated effects. Under these circumstances, the popular approximate continuum and numerical methods like the Rayleigh–Ritz and finite element methods are used to obtain reliable and accurate solutions to the initially loaded free vibration characteristics of these structural members. However, these approximate methods are also having their inherent difficulties. To avoid this, a simple but accurate formula is developed, which is very useful for the design engineers while dealing with structural members used in missiles and rockets. The use of master formula for the first mode and also higher modes of vibration has been shown for typical structural members. 相似文献
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对一种新型的预制管混凝土柱结构与钢筋混凝土现浇柱,以体积配箍率和预制管的混凝土轴心抗压强度为参数,进行对比试验。用二轴强度理论计算预制管混凝土柱的开裂荷载,并在本次试验和以往理论研究的基础上,给出预制管混凝土柱轴心受压承载力计算公式。 相似文献
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钢筋混凝土偏压剪扭构件的变形计算方法探讨 总被引:2,自引:0,他引:2
本文主要讨论了钢筋混凝土偏压剪扭构件在单调扭矩作用下刚度变化 ,对这种构件的变形进行了理论分析 ,提出了适用的计算公式 ,与已有的试验结果比较 ,符合良好。 相似文献
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根据新的《混凝土结构设计规范》(GB50010-2010)的裂缝计算公式,对受裂缝控制的普通受弯构件分别按不同强度等级的混凝土和钢筋进行计算.通过对计算结果进行分析,提出了选用钢筋和混凝土的强度等级时,宜根据环境类别进行选用,以充分利用钢筋和混凝土的强度,为设计人员用新规范进行混凝土结构设计提供参考. 相似文献
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A comparative study of AISC-360 and EC3 strength limit states 总被引:1,自引:1,他引:0
A study has been undertaken to evaluate the similarities and differences between the steel building design specifications
used in the United States and Europe. Expressions for nominal strength presented in the AISC-360 Specification and the Eurocode
3 Specification were compared for fundamental limit states. In particular, rules for cross-section classification, tension
members, compression members, I-shaped members subjected to flexure, I-shaped members subjected to shear, and fasteners were
studied. Results of the investigation revealed that, in general, both specifications provide nominal capacities that are close
to each other. Significant differences were reported for some limit states such as flexure in I-shaped members with non-compact
flanges, shear and lateral torsional buckling in I-shaped members, and bearing strength at bolt holes. In this paper, the
details of the comparative study are presented along with observations that are useful for practicing engineers. 相似文献
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本文讨论了钢筋混凝土构件在轴向力、弯矩和剪力共同作用下的抗剪强度。对171根构件试验结果的分析表明,用我国《钢筋混凝土结构设计规范》(TJ 10-74)中受弯构件的抗剪强度计算公式来计算偏压和偏拉构件的抗剪强度是不合适的,对于偏压构件偏于保守,而对于偏拉构件则偏于不安全。在分析试验资料的基础上,本文提出了一个考虑轴向压力和拉力影响的抗剪强度实用计算方法。计算结果与试验结果符合较好。 相似文献
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Michaela GKANTOU Marios THEOFANOUS Charalampos BANIOTOPOULOS 《Frontiers of Structural and Civil Engineering》2020,14(1):10
The structural behavior of prestressed high strength steel (HSS) tubular members is investigated through the execution of advanced finite element modeling. Numerical models are developed and validated against published experimental data on HSS tubular members subjected to different levels of initial prestress and loaded either in tension or compression. The effect of the presence or absence of grouting on the strength and ductility of the members is also considered. To numerically replicate the structural response recorded in the tests, some key modeling features including the employed numerical solver, the adopted material models and the element types warrant careful consideration. Upon developing of the finite element models, the numerically generated ultimate loads, the corresponding failure modes and the full load-deformation curves are compared to the experimental ones, indicating a successful validation. As anticipated, prestressing enhances the load-bearing capacity for the tensile members, whereas it is detrimental for the compressive ones. A series of parametric studies is performed to assess the influence of key factors on the structural response of prestressed HSS members and the obtained results are discussed. Design guidance for tensile and compressive prestressed tubular members is also provided. 相似文献