摘要
交叉撑杆和下弦分段连接的张弦梁结构,具有较高的抗连续倒塌性能,可以改进传统张弦梁结构抗连续倒塌性能较弱的不足,但其抗力计算方法尚未明确。为此,通过对管内穿索下弦与交叉撑杆的张弦梁结构在边节间和跨中节间索段两种失效情形下的抗力计算式的理论推导,基于动力放大系数和压弯构件承载力构建了连续倒塌抗力计算模型。采用ANSYS/LS-DYNA程序,建立了该类结构抗连续倒塌精细有限元模型,开展了不同上弦刚度、高跨比等参数下的承载力分析,明确了动力放大系数的变化规律。同时,采用多元线性回归方法,得到了动力放大系数的拟合计算式。结果表明,动力放大系数拟合效果较好,决定系数约为0.9;结合算例分析,提出的连续倒塌抗力计算模型具有较高的精度,与有限元分析结果相差仅10%左右。
Beam string structures with crossed struts and lower chord with segmented connections have high progressive collapse resistance,which can improve the weak progressive collapse resistance of traditional beam string structure.However,their resistance calculation method is not clear.Through theoretical derivation,the resistance calculation formulas of beam string structures with cable-in-pipe lower chords and crossed struts under two failure conditions of side span and mid-span cables were derived,and the calculation model of progressive collapse resistance was proposed based on dynamic amplification factor and bearing capacity of compression and bending members.Based on the ANSYS/LS-DYNA platform,a detailed finite element model was developed to simulate the structural progressive collapse.The bearing capacity was analyzed for varying upper chord stiffness and height-span ratio,and the variation law of dynamic amplification factor was clarified.A formula of the dynamic amplification factor was then derived by multiple linear regression method.The results show that the proposed dynamic amplification factor formula provides a good fit to the data,with a coefficient of determination around O.9.Combined with case study,the proposed resistance calculation model for progressive collapse exhibits high predictive accuracy,with only about a 10% deviation from the finite element analysis results.
作者
蒋友宝
王艺珺
吴春成
周浩
胡炜
张梦华
JIANG Youbao;WANG Yijun;WU Chuncheng;ZHOU Hao;HU Wei;ZHANG Menghua(Hunan Provincial Key Laboratory of Green Construction and Maintenance of Bridges and Buildings,Changsha University of Science and Technology,Changsha 410114,China;CCCC Construction Group Co.,Ltd,Beijing 100022,China)
出处
《建筑结构学报》
北大核心
2025年第11期237-249,共13页
Journal of Building Structures
基金
国家自然科学基金项目(52378126)
长沙理工大学研究生科研创新项目(CX20230865)。
关键词
张弦梁结构
管内穿索下弦
交叉撑杆
连续倒塌
动力放大系数
抗力计算
beam string structure
cable-in-pipe lower chord
crossed struts
progressive collapse
dynamical amplification factor
resistance calculation
