【作者】 陆曦；

【导师】 董军；

【作者基本信息】 南京工业大学 ， 结构工程， 2006， 硕士

【摘要】 冷成型薄壁钢构件可以加工成多种经济截面形式,受力性能较好,承载力较高,整体刚度较大,而且加工、制作简单,运输、安装方便,易于工业化,在轻钢龙骨体系住宅等结构中已被广泛采用。而目前冷成型钢构件的研究仅集中在弹性、静力荷载作用的范围内,对这类构件的滞回性能和抗震性能尚未深入研究。为了探索在抗震设防地区采用轻钢龙骨体系建造单层和多层住宅的适用性,对冷成型薄壁钢构件抗震性能进行研究具有重要的技术和经济意义。本文在国内外已有的研究成果基础上,采用有限元模型对冷成型薄壁钢构件在常轴力和循环弯矩共同作用下的滞回性能进行数值模拟。运用通用非线性有限元计算分析软件ABAQUS中考虑几何和材料非线性的九结点减缩积分薄壳单元S9R5,同时采用线性随动强化的材料本构关系考虑钢材包辛格效应以及冷加工效应等因素的影响建立有限元模型,并通过与已有理论和试验结果对比,验证了有限元模型的正确性。为研究普通C型钢在压弯循环荷载作用下的滞回性能,本文建立了常轴力、循环弯矩荷载下的C型钢构件有限元模型,分析了构件宽厚比和轴压比对冷成型薄壁C型钢构件滞回性能的影响规律,分析结果表明:宽厚比和轴压比对构件滞回性能影响显著,随着宽厚比的增加,构件承载、转动以及塑性变形能力降低;随着轴压比增加,构件的最大承载力降低,承载力退化;研究了此类构件在压弯循环荷载下的最终破坏形式;通过引入延性系数这一衡量标准对冷成型C型钢的抗震性能作出评价,并初步给出合理的设计建议。为解决普通C型钢宽厚比较大、滞回性能较差的缺点,本文首先对具有相同宽厚比的C型钢和加劲C型钢的滞回性能进行了比较,结果表明加劲可有效提高此类构件滞回性能;然后对具有中间加劲的C型钢在压弯循环荷载下的滞回性能、变形情况以及最终的破坏模式进行了深入分析;研究了加劲设置对构件性能的影响,得出了合理的加劲布置方式;利用延性系数对本文所计算的构件的抗震性能进行了评价,结果表明:通过加劲,绝大部分的C型钢都满足了延性要求;根据以上的分析结果,本文初步提出了具有中间加劲C型钢的宽厚比及轴压比限值,进而对冷成型薄壁钢构件的抗震设计提出了合理建议。本文研究表明:只要采取合理的措施,如限制构件宽厚比或设置中间加劲,就可以保证冷弯薄壁钢构件具有较好的抗震性能。这为以后进一步开展深入的理论和试验研究以及促进冷成型薄壁钢构件在抗震设防地区轻钢龙骨体系中的应用奠定了基础。更多还原

【Abstract】 All kinds of economical cross-section configurations of the cold-formed thin-wall steel (CFS) members can be produced by cold-forming operations, and consequently favorable section shape can be obtained. Besides, CFS members can be prone to process, transport, install and industrialize. At present, CFS members have been widely utilized as principle structural members in low-rise light-gauge steel framed residences. However, research on CFS members is mainly focused on the range of elastic and static performance, and the hysteretic behavior of CFS members has not been researched deep. To explore the feasibility of light-gauge steel framed residences in seismic fortified areas, the researches for the hysteretic behavior of CFS members has great technical and economic significance.Based on the research results of domestic and overseas, the hysteretic behavior of CFS members under constant compression and cyclic bending is numerically simulated by finite element method. Through the finite element nonlinear analysis program ABAQUS, this paper uses S9R5 thin shell element and the linear kinematic hardening model for simulating geometric and material nonlinearities and Bauschinger effect, strain hardening and intensity increase at corner zone to establish the finite element models of CFS members under constant compression and cyclic bending, and utilizes existing theory and experiment results to verify the validity of the finite element models.To study the hysteretic behavior of CFS members under constant compression and cyclic bending, this paper establish the finite element models of cold-formed thin-wall C-section steel members under constant compression and cyclic bending, analyses the effect of the width-to-thickness ratio and the axial compressive ratio on the hysteretic behavior of the cold-formed steel members. Analytic results indicated that the width-thickness ratio and the axial compressive ratio affect the hysteretic behavior of the member evidently, as the increase of the width-thickness ratio, the resistance, rotation capacity and plastic deformation capacity decreases; then this paper research the final failure modes of this kind of member under the cyclic loading; by introduce the ductility coefficient to assess the aseismatic behavior of Cold-Formed C steel members, and some rational design suggestion are drawn initially.Since the width-to-thickness ratio of common C-section CFS members is large, so the hysteretic behavior of this member is bad. To solve the weakness of this member, this paper compare the hysteretic behavior between the C-section and intermediate stiffeners C-section member which has the same width-to-thickness ratio. The compare result show that setting intermediate stiffeners is a effective method to improve the hysteretic behavior of CFS member. Then the hysteretic behavior, deformed shape and the final failure modes of this更多还原