【作者】 郭明星；

【导师】 樊江；

【作者基本信息】 昆明理工大学 ， 结构工程， 2010， 硕士

【摘要】 与国外先进技术相比,我国对冷弯薄壁型钢结构住宅体系的研究和应用起步比较晚。冷弯薄壁型构件宽厚比比较大,在竖向荷载作用下很容易发生局部屈曲、畸变屈曲和整体屈曲。现行国家规范把畸变屈曲作为局部屈曲对待,然而这种简化方法有时是不安全的。对于墙柱的竖向承载力,国家还没有出台相关规范条文。同时,随着构件截面复杂性增加,有效截面法计算过程越来越繁琐。因此,现有的计算方法和理论还存在不尽完善的地方。本文通过查阅国内外文献,对冷弯薄壁型构件的直接强度法计算理论进行了系统的研究,以期为此类构件的设计和应用起到积极的推动作用。1.本文首先介绍了冷弯薄壁型钢住宅的做法及特性,目前国内外应用情况及国内外冷弯薄壁型钢结构住宅竖向承载力研究现状。2.详细介绍了冷弯薄壁型柱的屈曲模式,分析了不同屈曲模式下屈曲应力的解法。根据铁木辛柯梁的稳定理论,推导出畸变屈曲应力计算公式。分析了翼缘宽度、腹板高度、卷边长度、板材厚度对畸变屈曲应力的影响。3.介绍了有效宽度的基本原理和国内外规范对有效宽度的规定。根据北美规范,推导了卷边的合理长度取值范围。参考有效截面法理论,完善了用于计算冷弯薄壁型构件竖向承载力的计算理论—直接强度法,并对其进行了详细分析。通过有效截面法计算理论,验证了直接强度法在计算裸柱承载力和破坏模式的适应性和科学性。4.介绍了墙柱的破坏模式,详细阐述了各种破坏模式下主柱屈曲应力的解法,建立了墙柱的直接强度法计算理论。通过有效截面法计算理论,验证了直接强度法在计算墙柱承载力的适应性和科学性。5.用试验结果验证了裸柱和墙柱有限元模型的正确性,通过大量的有限元分析,验证了冷弯薄壁型柱的直接强度法的正确性和实用性。最后,在上述研究的基础上总结全文得出主要结论,并结合当前国际和国内的研究方向,提出本文有待进一步完善的工作。更多还原

【Abstract】 Comparing with the overseas advanced level, our country is later in the research and application about the structural system of the cold-formed thin-wall steel residential building. For the ratio width-thickness of cold-formed thin-wall steel is bigger, element is easy to happen local buckling, distortional buckling or overall buckling when the structure bears the vertical load. The distortional bucking can be merged into local buckling calculation Current China Specification GB50018-2002 which is sometimes unsafe. There are no provisions for cold-formed thin-wall column with sheathing bracing in Current China Specification. At same times calculating process of effective section method becomes more and more cumbersome as section of cold-formed thin-wall column complex. So Current China Specification should be supplemented and improved. Based on relatively domestic and international existing research achievements the direct strength methods in calculating the vertical capacity of cold-formed thin-wall members between sheathing-bracing and non-sheathing-bracing is derived in order to promote design and application of cold-formed thin-wall steel member.1. This article introduces the characteristics of the cold-formed thin-wall steel residential buildings and the application of this structural system and the research status of the cold-formed thin-wall steel residential buildings system under the vertical force at home and abroad in recently years.2. Introduce the buckling modes of cold-formed thin-wall columns and the calculating methods of different buckling stresses. Based on Timoshenko beam stability theory the formula in calculating distortional buckling stress is derived. The law of distortional buckling stress relevant to parameters of section such as different section height and with or thickness is specially analyzed.3. Introduce basic principle of effective width and domestic and international technical code of effective section. The rational range of length of lip is given according to AISI. According to effective section method the direct strength methods in calculating the capacity of cold-formed thin-wall members without sheathing-bracing is derived, which is also specially analyzed. Using the effective section methods verify the direct strength method in calculating the capacity of the cold-formed thin-wall without sheathing bracing in validity and utility.4. Introduce failure modes of cold-formed thin-wall column with sheathing bracing (wall-column) and the calculating methods of different buckling stresses. The direct strength method in calculating the capacity of wall-column is also created, verified by effective section method in validity and utility.5. Test results verify the correctness of the finite element models of cold-formed thin-wall members without sheathing-bracing and with sheathing-bracing. The direct strength methods in calculating the capacity of the cold-formed thin-wall without sheathing bracing is verified in validity and utility by a large number of finite element analysis.Finally, on the basis of the above main conclusions is summed up and propose improved work in this paper according to recently research direction at home and abroad is also presented.更多还原