【作者】 董毅；

【导师】 杨兆华； 赵国华；

【作者基本信息】 吉林大学 ， 建筑与土木工程， 2006， 硕士

【摘要】 随着国民经济的快速发展,人们对物质文化生活需求的日益提高,使建筑结构已面临着新的挑战,人们总想在有限的建筑面积和空间内获得最好的使用功能和最佳的投资回报,由此促进了建筑结构向着大柱网、大开间、大跨度及多功能方向发展,而传统的结构在某些方面已满足不了其要求,钢与混凝土组合结构以其承载力高、自重轻、节约材料、截面尺寸小、抗震性能好及改善结构功能等突出优点,迎合着建筑结构的发展。钢与混凝土组合结构在很多实际工程中得到了应用,尤其是近20年来该结构已在大跨度桥梁、工业厂房及高层与超高层建筑等重要工程中得到广泛应用,取得了良好的经济和社会效益。广大工程技术人员在理论研究方面也做了大量工作,钢与混凝土组合梁在国内外也已得到较为广泛的应用和研究,已形成弹性和塑性计算理论。但与钢筋混凝土结构和钢结构相比,对组合结构的研究和实验工作还不够充分,在对组合梁承载力尤其是截面抗剪承载力的研究上还不够深入。大多有关组合梁的设计是在吸取国外经验,结合我国的材料和结构特性,总结工程实践和研究实验成果的基础上建立的。其计算理论基本上是沿用国外的设计规范中的计算理论。在计算抗弯承载力时,不计板托作用,计算截面抗剪承载力时,不计混凝土部分的抗剪作用,这些简化对于有托尤其是深托组合梁是保守的。本文对组合梁的承载力进行了研究,在弹性分析中摒弃了换算截面的概念,基于组合梁本身,在基本假定的前提下,通过力学分析,得出了组合梁的弹性抗弯和抗剪计算公式。这些公式在形式上符合设计者的习惯,且考虑了板托的影响,计算精度优于换算截面法。在组合梁的塑性分析中,本文提出以组合梁外边缘纤维层达到极限应变为最终承载力极限状态,推导出在这种极限状态时在纯弯作用下组合梁的抗弯承载力计算公式,推导出计及混凝土部分抗剪作用的组合梁抗剪承载力计算公式,着重分析了组合梁在弯剪共同作用下的承载力计算方法,提出了判断组合梁是否破坏的准则。更多还原

【Abstract】 Composite beams of steel and concrete are new type structures in which the steel beams and the concrete board are integrated by shearing force connectors to take advantage of the respectives of tension and compression.As this composite structures have merits of both steel and concrete and overcome their shortcoming,so its performance is more than a single structure made of superior materials,notable benefit of technology and economics have been achieved.The first investigation of composite beams of steel and concrete began in the early 20th Century.Looking back at the course of development of the composite beams of steel and concrete,the research and application of composite beams has been several decades of history. Though composite beams have been applied and researched extensively, it is not enough in investigating and experimenting the composite and carrying capacity especially of the vertical shear of cross-section with respect to reinforced concrete structures and steel structures.The composite beam section in our Steel Structure Design Code(GBJ50017-2003) has been established by learning from foreign experience、combining our material and structural properties and on the basis of the results of experimental studies of China Engineering. The calculation theory- Flexibility theory and Simplified Plastic theory is basically following the design specifications of the foreign theory.without considering the concrete haunch in calculating the moment of resistance and the whole concrete portion in calculating the resistance to vertical shear.Such simplification is conservative for composite beams with haunches especially with deep haunches.In this paper,in the light of above-mentioned problem research in the stress condition and failure of composite beams is done first,and then a new method is proposed through theoretical analysis based on properties of the composite beam. In the elastic analysis of composite beams,the concept of changing section is given up.Based on composite beam itself and under the premise of the basic assumptions,the formulas to the resistance in elastic state and to the resisting shear that considering the contribution of the concrete haunch on the action are then given by mechanical analysis. These formulas accord with the designer’s habit in the form and consider the influence of the concrete haunch. And the precision is superior than the conversion section method.In the plastic analysis of composite beams,it is proposed that the composite beam arrives at the ultimate limit states of capacity when the stain of the outside edge of the cross-section reaches the ultimate stain.The formulas to the moment of resistance on the action of the pure moment and to the resisting shear considering the contribution of the concrete haunch on the action of更多还原