【作者】 马淑欣；

【导师】 杨树标；

【作者基本信息】 河北工程大学 ， 结构工程， 2008， 硕士

【摘要】 钢结构交错桁架作为一种新型结构体系,国内外已对其进行了一定的理论分析,并且有了一些工程实践。在此基础上,本文对交错桁架结构体系的结构特点、简化的计算理论、受力特性、杆件设计方法进行了分析研究,并应用静力非线性push-over分析方法对该体系的相关参数进行了深入研究。主要完成了以下工作:(1)对交错桁架结构体系的抗震布置原则、作用计算理论、抗侧刚度的简化计算方法、竖向和水平地震作用下内力的简化计算方法进行了分析总结。(2)应用ETABS分析软件,对交错桁架结构体系在竖向荷载及水平地震作用下的受力性能进行了研究,得到了各杆件在弹性范围内的轴力、剪力及弯矩的分布特点。同时对水平地震作用下的振型和变形进行了分析验算,阐明了各杆件的强度和稳定计算方法。(3)应用push-over分析方法得出:在8度罕遇地震作用下,本文中的算例均满足抗震设防要求。同时确定了混合式交错桁架结构体系的能力谱曲线、塑性铰的发展顺序和结构破坏模式。总体说来,塑性铰是由下而上,从空腹节间逐渐向两边发展的。混合式交错桁架结构体系的柱没有出现塑性铰,塑性铰大部分集中在下部桁架中的斜腹杆上,使结构的一层或二层成为薄弱层。(4)通过对不同参数设置的交错桁架结构体系的push-over分析,得出如下结论:在8度罕遇地震作用下,除在结构底部外,高宽比增大,层间位移角增大;长宽比增大,下部层间位移角和上部层位移明显增大;采用风撑和加设横向支撑或纵向支撑能有效减小结构薄弱层的层间位移角,在实际设计中可适当采用。并建议在抗震设防区,宜采用钢管混凝土柱或落地式桁架。本文系统地阐述了交错桁架结构体系的设计理论和方法,并对其进行了抗震性能评价,帮助设计者找到改善该新型结构体系抗震性能的方法,同时给出一些带有规律性的结论和建议,便于该结构体系的应用推广。更多还原

【Abstract】 As a new type system of steel structure, the staggered truss system has been analyzed theoretically and applied into some projects internationally. On this basis, the structure features, simplified calculation method, force characteristics under different loads and design theory of members are studied. Then, the effects of different factor settings on staggered truss systems are researched deeply by static nonlinear analysis Push-over. The main conclusions are outlined as the following:Frist, the contents including layout principles for earthquake resistance, theoretical calculation for loads, simplified method of lateral stiffness, internal forces calculation method under vertical loads and horizontal earthquake are systematically summarized.Second, under vertical loads and horizontal earthquake, the Load-bearing Capacities of Staggered Truss Structure are researched by analysis software Etabs. The distributions of internal forces are abtained within the extent of elasticity. In addition, the vibration modes and deformation under horizontal seismic actions are analized. The design method for the members of staggered truss is illustrated including both intensity and stability.Third, from the push-over analysis, all the examples of this paper can satisfy seismic fortification requirement under rare earthquake of intensity 8. Also, the curves of Capacity Spectrum, development of plastic hinges, destruction pattern of the hybrid staggered truss are determined. All in all, the plastic hinges develop gradually from lower to upper, Vierendeel panel to both sides. Finally, most of the plastic hinges are appeared on the tilted belly poles of the lower trusses, but not on the side columns. Because of this, the first or second floor becomes the weakest parts of the hybrid staggered truss.Forth, through push-over analysis of hybrid staggered truss with different parameters, the conclusions are as following: under rare earthquake of intensity 8, besides the first story, when the ratio of height to width increases, the inter-story drifts increase; As the ratio of length-width increases, both the lower inter-story drift and the upper story displacement obviously enlarge; Moreover, the inter-story drift of weakness floors can be effectively reduced by using wind bracing instead of diagonal brace or adding lateral brace or setting longitudinal brace. Also, the concrete filled steel tube and setting truss on the first floor are suggested in the regions seismic fortification.Design theories and methods of the staggered truss system are illustrated in the paper. Then, it’s aseismic behavior is evaluated to help engineers find ways to improve the new structural seismic performance. Meanwhile, some regular conclusions and suggestions are given making the system applicated and generalized conveniently.更多还原