纤维增强复材组合平面桁架破坏性试验研究

DESTRUCTIVE TEST STUDY OF FRP COMBINED PLANE TRUSS

近年来,纤维增强复材(FRP)因质量轻、抗拉强度高和耐腐蚀等特点在土木工程领域得到逐步推广,其应用也由加固、补强逐渐向作为结构主要承力构件方面发展。通过以等截面的FRP拉挤圆管与钢管相结合,设计并制作了一榀4 m长、1 m高的钢-FRP组合平面桁架,通过在跨中施加竖向集中荷载,研究钢-FRP组合结构节点、杆件稳定性和FRP组合结构整体的力学性能。研究结果表明:钢-FRP组合平面桁架中各杆件间实测应变的比值关系与理论计算得到的内力系数的比值关系吻合良好,最终破坏模式为:桁架某连接节点处的FRP管发生轴向劈裂-剪切破坏,当桁架破坏时,FRP拉挤型材的材料利用率超过50%;最后根据破坏模式提出了设计建议。

In recent years,FRP has been gradually promoted in the field of civil engineering due to its lightweight,high tensile strength and corrosion resistance.Its application has also evolved from reinforcement to the main component of the structure.In the paper,an equal-section FRP pultrusion pipe was combined with an equal-section steel pipe to design and manufacture a steel-FRP combined plane truss with a length of 4 m and a height of 1 m.The stability of steel-FRP composite structural connections and the overall mechanical properties of FRP composite structures were studied by applying vertical concentrated loads in the middle of the truss.The results showed that the measured strain ratio of the rod in the steel-FRP combined plane truss was consistent with the internal force coefficient ratio.The final failure mode was:FRP tube splitting-shear failure;when the truss was destroyed,the material utilization ratio of the FRP pultruded profile reached 50%;at the same time,some design suggestions were introduced according to the failure mode.