负载下碳纤维加固工字形受弯钢梁试验研究

Experimental Study on I-shaped Flexural Steel Beams Strengthened with CFRP under Load

随着经济发展,碳纤维复合材料加固结构构件普遍应用于工程实际中。论文通过对不同碳布加固长度、不同负载水平、不同加固层数及不同端部锚固情况下的工字形钢梁进行碳纤维布加固试验,汇总了负载水平、锚固措施、加固量等对加固工字形钢梁的力学性能的影响,为工程实践提供参考作用,得到以下结论:(1)工字形钢梁破坏形态主要为碳纤维布被拉断、工字形钢梁弯曲破坏、碳布端部发生剥离破坏;(2)与对比试件相比较,对于不同参数的工字形钢梁,随着加固量的提高,各特征荷载均有不同程度提高,但随着加固量的提高,其提高幅度有所下降;(3)不同加固参数下工字形钢梁其截面应变分布近似呈线性规律,基本符合平截面假定;(4)负载条件下工字形钢梁的荷载-跨中挠度曲线与对比试件基本相似,不同加固参数工字形钢梁刚度均有不同程度提高;(5)碳布应力主要集中在试件中间,相应的端部应力较低。

With the development of economy,structural members strengthened with carbon fiber composites are widely used in engineering practice.In this paper,I shaped steel beams strengthened with CFRP under different CFRP reinforcement lengths,different load levels,different reinforcement layers and different end anchorages are tested,and the effects of load levels,anchorage measures and reinforcement quantities on the mechanical properties of strengthened I shaped steel beams are summarized,which can provide reference for engineering practice.The following conclusions are drawn:①the main failure modes of I shaped steel beams are:the carbon fiber sheets are pulled off The I-shaped beam is bent and damaged,and the end of carbon cloth is peeled;②compared with the comparison specimens,for I-shaped steel beams with different parameters,with the increase of the reinforcement amount,each characteristic load has increased in varying degrees,but with the increase of the reinforcement amount,the increase range has decreased;③under different reinforcement parameters,the section strain distribution of I-shaped steel beams is approximately linear,which basically conforms to the plane section assumption;④the load mid span deflection curves of I-shaped steel beams under load conditions are basically similar to those of the comparison specimens,and the rigidity of I-shaped beams with different reinforcement parameters is improved to varying degrees;⑤the carbon cloth stress is mainly concentrated in the middle of the specimen,and the corresponding end stressis low.