钢筋混凝土叠层空腹桁架转换结构热力耦合反应分析  

Thermal Mechanical Coupling Analysis of Reinforced Concrete Transfer Structure with Superimposed Vierendeel Truss

作　　者：孔维一[1] 傅传国[2] 褚飞[2] 王玉镯[2] 

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]山东建筑大学土木工程学院,山东济南250101

出　　处：《防灾减灾工程学报》2016年第3期386-393,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51278289;51478254)资助

摘　　要：结合某实际大跨度转换结构工程,建立了一榀三层底部大空间钢筋混凝土叠层空腹桁架转换结构模型。采用ABAQUS大型有限元分析软件,对该转换结构模型施加标准升温及恒定竖向荷载的共同作用,进行了9种受火工况下转换结构模型的变形计算与分析,绘制了模型观测点位移与标准升温时间的关系曲线。计算分析结果显示,不同受火工况下,随着升温时间的增加,转换结构模型在常温竖向力学荷载作用下变形的基础上皆产生了复杂的附加变形。受火工况4的受火情形对底部托梁竖向变形的影响最为明显,其次是受火工况2,随着升温时间的增加,竖向变形速率较快且不收敛。托梁沿梁跨挠度曲线的对称性与受火房间位置的对称性保持一致,在非对称受火工况下,底部托梁沿跨度挠度峰值出现在转换结构模型对称轴的受火房间一侧,且边跨受火工况较为不利。随着升温时间的增加,不同受火工况下转换结构模型两侧边柱的水平侧移逐渐增大。由于受火楼层横梁受火膨胀变形的作用,受火楼层横梁位置处边柱向外凸出的侧移明显大于其他楼层。Based on a practical engineering of large span transfer structure, the model of 3-story reinforced concrete transfer structure with superimposed vierendeel truss is established. The non- linear FEM software ABAQUS is used to analyse the deformation of the model, which is exposed to standard fire and coupling with vertical loads. Based on the simulation results of 9 fire cases, the displacements of measured points and heating-up time curves are plotted. The numerical results show that on the basis of the deformations under vertical loads at normal temperature, the transfer structure models produce complicated additive deformations with the heating-up time in- creasing. As to the effects of 9 fire cases, the fourth fire case has important effect on vertical de- formation of the bottom joists, followed by the second fire case. With the heating-up time increasing, the vertical deformation is fast and not convergent. The symmetry of the deflection curves along transfer girder span is consistent with the symmetry of fire cases, and the deflection peak of transfer girder appears in the side of the room on fire in the unsymmetry fire cases. The cases of side span on fire are unfavorable. With the heating-up time increasing, the lateral displacements of two side columns of the model increase gradually in different fire cases. Because of the thermal expansion of the beam in burning floor, the lateral displacements outward of side columns in burning floors are significantly larger than other floors.

关 键 词：钢筋混凝土 转换结构 火灾 变形分析 

分 类 号：TU375[建筑科学—结构工程]