钢—混组合桁架节点处PBL剪力键群受力性能研究

发布时间：2019-04-29 07:02

【摘要】：采用有限元分析软件ABAQUS建立整体耳板式、分离耳板式和外接式3种钢—混组合桁架节点的简化模型,计算1倍、2倍、3倍设计荷载作用下各类型节点处PBL剪力键的水平和竖向滑移,然后根据单根PBL剪力键的荷载—滑移关系反推PBL剪力键的负载,进而研究PBL剪力键群的负载分布规律及其受力性能。结果表明:节点处同行PBL剪力键的水平负载分布呈"不平衡对称"模式,竖向负载分布呈"反对称"模式,PBL剪力键群的负载以水平方向为主,且荷载中心线与PBL剪力键群中心线不重合是导致PBL剪力键群水平负载不均匀程度增加的主要原因;随荷载的增加,PBL剪力键群的水平负载最终趋于相对均匀,而其竖向负载的不均匀性无明显变化;依据工程要求,提出将单根剪力键负载控制在其弹性极限荷载内或在0.576倍极限承载力内的校核方法,以保证疲劳破坏不从剪力键群开始或疲劳寿命在200万次以上的设计要求,据此对3种类型节点处PBL剪力键群的校核结果表明,其强度和疲劳性能均能满足要求;整体耳板式节点的强度储备最大,外接式次之,分离耳板式最小。
[Abstract]:The finite element analysis software ABAQUS is used to set up the simplified model of three kinds of steel-concrete composite truss joints, that is, the integral ear plate, the separation of the ear plate and the external joint, and the calculation is 1 times and 2 times, respectively. The horizontal and vertical slip of PBL shear bond at each type of joint under 3 times design load, and then reverse the load of PBL shear bond according to the load-slip relation of single PBL shear key. Furthermore, the load distribution and mechanical performance of PBL shear bond group are studied. The results show that the horizontal load distribution of PBL shear keys at nodes is "unbalanced and symmetrical", and the vertical load distribution is "anti-symmetric". The load of PBL shear bond groups is mainly in horizontal direction. The non-coincidence between the load centerline and the center line of the PBL shear bond group is the main reason for the increase of the horizontal load inhomogeneity of the PBL shear bond group. With the increase of load, the horizontal load of PBL shear bond group finally tends to be relatively uniform, but the vertical load inhomogeneity of the shear bond group has no obvious change. According to the engineering requirements, a checking method is proposed to control the load of a single shear bond in its elastic limit load or in the limit bearing capacity of 0.576 times. In order to ensure that fatigue failure does not start from shear bond group or fatigue life is more than 2 million times, the results of checking the PBL shear bond group at three types of joints show that its strength and fatigue performance can meet the requirements. The strength reserve of the whole ear plate joint is the largest, the external type is the second, and the separation ear plate is the smallest.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金资助项目(50908230) 铁道部科技研究开发计划项目(2012G007-B)
【分类号】：U441

【相似文献】