带二分拉杆的FRP复合横担受力性能试验研究

Experimental study on the mechanical performance of FRP composite crossarm with split tie rod

基于“三拉一压”复合横担,提出了一种带二分拉杆的FRP复合横担,解决了横担与塔身连接构造不合理的问题,同时保证了横担有足够的刚度。对带二分拉杆的FRP复合横担进行静力试验,研究其承载性能和破坏模式。结果表明:横担的荷载与位移基本成线性变化规律;复合材表面未出现明显变形;横担梁复合材应变远大于其钢套管应变,且越靠近加载端应变越大;受拉侧拉杆复合材应变大于横担梁复合材应变,说明受拉侧拉杆受力较横担梁大,更易发生破坏;横担的失效形式为受拉侧拉杆复合材和钢套管之间的胶接滑移破坏,拉杆的承载力决定了横担的极限承载力。横担在设计荷载以及破坏荷载作用下各构件截面应变均处于弹性阶段,其纵向破坏荷载约为设计荷载的5倍,说明该横担具有良好的受力性能,有较大的安全裕度。

Based on the“three pulling and one pressing”composite crossarm,a FRP composite crossarm with split tie rod is proposed.The problem of unreasonable connection structure between the crossarm and the tower body is solved,and sufficient stiffness of the crossarm is ensured.The static test of FRP composite crossarm with split tie rod is carried out to study its bearing performance and failure mode.The results show that the load and displacement of the crossarm basically change linearly;There is no obvious deformation on the surface of the composite;the strain of the composite of the crossarm beam is much greater than that of the steel sleeve,and the closer it is to the loading end,the greater the strain is;The strain of the tension side tie rod composite is greater than that of the crossarm beam composite,which indicates that the tension side tie rod is more stressed than the crossarm beam and is more prone to damage;The failure mode of the crossarm is the adhesive slip failure between the tension side tie rod composite and the steel sleeve.The bearing capacity of the tie rod determines the ultimate bearing capacity of the crossarm.Under the design load and failure load,the section strain of each member of the crossarm is in the elastic stage,and its longitudinal failure load is about 5 times of the design load,indicating that the crossarm has good mechanical performance and large safety margin.