疲劳荷载作用下钢-混凝土组合梁变形计算  

Calculation of Deformation of Steel-concrete Composite Beam under Fatigue Load

作　　者：罗鑫源 倪永军[2] 马观领 LUO Xin-yuan;NI Yong-jun;MA Guan-ling(Henan Provincial Communications Planning&Design Institute Co.,Ltd.,Zhengzhou Henan 450052,China;Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]河南省交通规划设计研究院股份有限公司,河南郑州450052 [2]北京交通大学,北京100044

出　　处：《公路交通科技》2022年第5期85-94,共10页Journal of Highway and Transportation Research and Development

基　　金：青海省科技计划项目(2017-SF-139)。

摘　　要：为了对钢-混凝土组合梁在疲劳荷载作用下的弹性挠度和残余挠度分析,建立了组合梁疲劳荷载下的非连续传力模型。通过建立钢材和栓钉等材料的疲劳损伤退化模型,对组合梁在疲劳荷载情况下沿梁长方向的滑移分布情况和跨中挠度进行了计算。结合不同连接程度的组合梁疲劳试验数据,进行了参数分析,并验证了方法的可靠性。提出了疲劳荷载作用下钢-混凝土组合梁变形计算公式,采用该模型计算的滑移值、弹性挠度值与试验值有较高的吻合度。当考虑沿梁长方向各排栓钉的刚度退化情况时,对于组合梁变形计算有较大的影响。通过混凝土承担的轴力和弯矩可知,疲劳荷载作用下,栓钉承载能力降低造成组合梁截面曲率增大,刚度降低,自身截面刚度的退化影响较小。计算结果表明:在疲劳荷载加载时,组合梁界面栓钉出现剪力重分布现象,跨中栓钉承担的剪力由小变大,靠近梁端栓钉承担的剪力由大变小,且呈非线性变化趋势。当接近组合梁疲劳寿命时,组合梁跨中变形、截面滑移都呈指数型上升趋势。当达到疲劳寿命时,梁端栓钉承担的剪力急剧下降,最终造成以栓钉剪切疲劳破坏形式的组合梁疲劳破坏。该方法可供实际试验和工程实际参考。In order to analyze the elastic deflection and residual deflection of steel-concrete composite beam under fatigue load,a discontinuous force transmission model of composite beam under fatigue load is established.By establishing the fatigue damage degradation models of steel and studs,the slip distribution along the beam length and mid-span deflection of composite beams under fatigue load are calculated.Combining with the fatigue test data of the composite beams with different connection degrees,the parameter analysis is carried out,and the reliability of the method is verified.The calculation formula for the deformation of steel-concrete composite beams under fatigue load is proposed.The slip values and elastic deflection values calculated by this model are in good agreement with the experimental values.When considering the stiffness degradation of each row of studs along the beam length,it has a great influence on the deformation calculation of composite beams.From the axial force and bending moment borne by the concrete,it can be seen that under the action of fatigue load,the reduction of the bearing capacity of the studs will lead to an increase in the curvature of the composite beam section and a decrease in the stiffness,and the influence on the stiffness of its own section is little.The calculation result shows that(1)When the fatigue load is loaded,the shear force redistribution of the studs at the interface of the composite beam occurs,the shear force borne by the studs in the mid-span changes from small to large,the shear force borne by the studs near the beam end changes from large to small,and the shear force is non-linear.(2)When approaching the fatigue life of composite beams,the mid-span deformation and section slip of composite beams all show the exponential upward trend.When the fatigue life is reached,the shear force borne by the studs at the beam end drops sharply,resulting in fatigue failure of the composite beam in the form of shear fatigue failure of the studs.This method can be used for prac

关 键 词：桥梁工程 变形 非连续传力模型 钢-混组合梁 数值分析 疲劳性能 界面滑移 

分 类 号：U448.38[建筑科学—桥梁与隧道工程]