导　　师： 郭成喜

学科专业： 081402

授予学位： 硕士

作　　者： ;

机构地区： 西安建筑科技大学

摘　　要： 随着轻质高强围护结构体系的发展,建筑钢结构中承重构件实现了轻型化,薄壁杆件的应用日益增多。组成构件的板件宽厚比较大时,板件在压力作用下易局部屈曲,但这并不意味着构件整体承载力的丧失,即板件具有屈曲后强度,利用板件的屈曲后强度可以产生明显的经济效益。我国现行《钢结构设计规范》/(GB50017-2003/),《冷弯薄壁型钢规范》/(GB50018-2002/)和《门式刚架轻型房屋钢结构技术规程》/(CECS 102:2002/)分别利用有效宽度法来考虑腹板局部屈曲后强度对受压构件稳定承载力的影响,但三种规范、规程中考虑腹板局部屈曲后强度的有效宽度计算方法各不相同,且各有不足之处。 本文引用国际上最新的试验资料,利用有限元软件,考虑了材料非线性和初始几何缺陷的影响,研究了翼缘宽厚比、腹板高厚比、构件长细比、材料屈服强度等参数变化对构件整体稳定的影响。分析结果表明几种参数对焊接薄壁轴心受压构件的局部和整体稳定都有不同程度的影响,且局部屈曲和整体屈曲相关作用对此类构件极限承载力的影响不可忽视。焊接薄壁受压构件整体稳定分析应该考虑局部和整体屈曲的相互影响,设计时可以利用其腹板屈曲后强度。 将有限元分析得到的焊接薄壁轴心受压构件的整体稳定承载力与《钢规》、《冷规》、《门规》以及直接强度法计算结果加以比较,指出国内规范和规程计算此类受压构件极限承载力通常是保守的,直接强度法较适合计算此类构件稳定承载力。 在有限元计算结果的基础上,本文提出了计算焊接轴心受压构件极限承载力的直接强度法公式,与已有直接强度法计算公式计算结果比较表明,本文建议公式是可靠的。 With the development of high strength and light weight enclosing structure system, thin-walled members are widely used in the steel structure,which makes the weight-bearing structure becomes lighter.When the width-thickness ratio of the plate is larger than the slenderness limit values,the plate will buckle easier under compression. However,the carrying capacity of the member doesn't lose because of the post-buckling strength of the plate.And it will produce evident economic benefits that using the post-buckling strength of the plate.The effective width method is adopted in considering the post-buckling strength of the web in Chinese code,for example 'Code for design of steel structures/(GB50017-2003/)','Specification for the design of thin-wall steel structures/(GB50018-2002/)' and 'Technical Specification for Steel Structure of Light-Weight Building with Gabled Frames'/(CECS 102:2002/) which have different regulations and defects in considering the post-buckling strength of the web. In this paper,considering material nonlinearity and initial geometry defects, width-thickness ratio of the flange and web,slenderness ratio of the member and yield strength of the material,the overall stability bearing capacity of welded thin-walled H-section members under axially compression is analyzed by finite element method. The results show that the parameters above all have various effects on the local and general stability of the thin-walled welded axially compressed members.The buckling interaction should be considered and the web's post-buckling strength could be used when doing global analysis on the thin-walled welded axially compressed members. The carrying capacity of the thin-walled welded axially compressed members which calculated by FEM are compared with the results calculated by the Chinese Codes and the Direct Strength Method,respectively.The comparison shows that the results predicted by the Codes of our country are conservative and the Direct Strength Method is accurate to predict the ultimate stren

关 键 词： 焊接 形薄壁轴心受压构件 局部屈曲 整体屈曲 相关屈曲 屈曲后强度 直接强度法

领　　域： [建筑科学]