钢-FRP异质单帽形件弯曲性能试验研究

Experimental study on flexural performance of steel-FRP hybrid top-hat structures

对钢-FRP异质单帽形件的弯曲性能进行了试验研究,该钢-FRP异质单帽形件由低碳钢和碳纤维(CF)或芳纶纤维(AF)单向布通过环氧树脂粘贴而成。通过三点弯曲试验,获得了包含不同FRP材料种类、粘贴位置、纤维方向的钢-FRP异质单帽形件的弯曲载荷-位移关系,并与钢质单帽形件进行比较。结果显示,钢-FRP异质单帽形件较钢质单帽形件具有更好的弯曲刚度、承载能力及更优的抗屈曲失稳能力。在单帽形件上顶面内侧沿构件长度方向粘贴FRP纤维及在侧壁内侧沿高度方向粘贴FRP纤维可以获得更好的弯曲性能,同时采用以上两种FRP粘贴方式的钢-FRP异质单帽形件的弯曲刚度、最大弯曲载荷和产生最大弯曲载荷时的位移分别较钢质单帽形件提升了50. 0%、64. 1%和24. 3%。

The flexural performance of steel-FRP hybrid top-hat structures was experimentally studied.The steel-FRP hybrid top-hat structures were fabricated with mild steel,and reinforced by carbon fiber(CF)or aramid fiber(AF)unidirectional fabrics.The two respective constituents of hybrid structure were adherent with epoxy matrix.Based on the three-point bending tests,the flexural load-displacement curves of the hybrid structures varied in the type of FRP,the location and the fiber direction of FRP reinforcement were gained and compared with steel top-hat structure.The results show that the steel-FRP hybrid top-hat structures exhibit significantly higher hending stiffness,flexural loading capability and better buckling resistance in the bending process compared with steel top-hat structure.The flexural performance can be better by the reinforcement of FRP at the internal surface of the top surface along the length direction and at the internal surface of the sidewall along the height direction of the top-hat structure.The bending stiffness,the maximum flexural load and the corresponding displacement of the hybrid top-hat structure with both suggested reinforcements are improved 50.0%,64.1%and 24.3%compared with steel top-hat structure,respectively.