锚杆钢-木组合托盘极限承载力学性能研究

Study on mechanical properties of steel-wood composite bolt tray under ultimate load

为降低动压冲击对支护系统的破坏,适应大变形巷道的需要;基于球壳结构理论构建锚杆拱形钢托盘承载力学模型,给出钢托盘最大承载力计算式,分析钢托盘各参数尺寸对其承载力的影响关系,研究木托盘压缩实验特征;通过Abaqus软件对钢托盘与组合托盘开展有限元静态力学强度实验,对比分析钢托盘与组合托盘受压状态下的不同特征,分析让压距离对组合托盘承载性能的影响规律。结果表明:对钢托盘承载力的影响顺序为拱高>拱底圆半径>孔口半径,拱高与承载力服从对数增加关系,拱底圆半径、孔口半径与托盘承载力基本成线性增加关系;钢-木组合托盘中木托盘先受力,并经历了压密阶段、弹性变形阶段和塑性变形阶段,木托盘被压缩可降低钢托盘30.03%的承载受力,组合托盘的应力-位移曲线右移,组合托盘的极限承载力增加;钢托盘受压破坏从孔口处开始,基本成圆形向四周扩展,托盘底部四边中间区域与四角区域形成的高应力差是导致托盘四角破坏的主要原因。

In order to reduce the damage of dynamic pressure impact to the support system and meet the needs of large deformation roadway,the bearing capacity model of anchor arch steel tray was constructed based on the spherical shell structure theory.The calculation formula of the maximum bearing capacity of steel tray was given.The influence of each parameter size of steel tray on its bearing capacity was analyzed.The characteristics of wood tray compression experiment were studied.The finite element static mechanical strength experiment of steel tray and composite tray was carried out by Abaqus software.The different characteristics of steel tray and composite tray under compression were compared and analyzed,and the influence of yield distance on the bearing capacity of composite tray was analyzed.The results show that the order of influence on the bearing capacity of steel pallet is arch height>radius of arch bottom circle>radius of orifice.The arch height and bearing capacity obey the logarithmic increase relationship,and the radius of arch bottom circle and orifice radius basically increase linearly with the bearing capacity of pallet.The wooden pallet in the steel-wood composite pallet is subjected to the force first,and has experienced the compaction stage,the elastic deformation stage and the plastic deformation stage.The compression of the wooden pallet can reduce the bearing force of the steel pallet by 30.03%.The stress-displacement curve of the composite pallet moves to the right,and the ultimate bearing capacity of the composite pallet increases.The compressive failure of the steel tray starts from the orifice and basically expands in a circular shape to the surrounding area.The high stress difference between the middle area and the four corner areas at the bottom of the tray is the main reason for the four corners failure of the tray.