纤维增强复合材料加固木梁受弯性能试验研究

EXPERIMENTAL STUDY ON FLEXIONAL BEHAVIOR OF TIMBER BEAM STRENGTHENED WITH FRP

对36根纤维增强复合材料(FRP)加固木梁的受弯性能进行研究。详细探讨受载后试件的工作机理和破坏模式。试件的设计参数为FRP的层数、FRP的类型及加固层的位置。分析各设计参数对加固木梁承载力和挠度的影响。试验结果表明,在木梁受拉区布置FRP可有效提高木梁的受弯承载力,受拉区粘贴一层CFRP可提高木梁受弯承载力30.61%。在纯弯区横向布置FRP可增强木梁受压区的性能,有效提高木梁的受弯承载力,提高的幅度与横向FRP层数有关。FRP加固木梁的破坏表现为受压区木纤维褶皱失稳、受拉区木纤维和FRP加固层被拉断。木梁受压区设置FRP加固层对受弯承载力的影响与加固的方式有关,受压区横向缠绕FRP加固效果最好,而沿梁纵向加固的效果并不明显。

The experimental investigation concerning the flexional behavior of 36 cylindrical wood beams reinforced with FRP sheets were conducted. The work mechanis^n and failure modes of the specimens were discussed in details. The parameters of the specimens were number, types and the location of FRP sheets. The effect of design parameters of the specimens on the carrying capacity and deflection of beams was analyzed. The results show that FRP in the tension zone of the wood beam can improve the capacity effectively. The capacity of wood beam is increased by 30.61% with one layer sheet of CFRP in tension zone. The lateral FRP wound in the pure flexion zone can improve the behavior of the compression zone of wood beam, and increase its flexional capacity effectively. The increasedextent is related with the number of FRP sheets. The failure of reinforced wood beam presents the folded fiber in the compressive zone and broken wood fiber in the tension zone. The effect of FRP in the compression zone on the bending capacity uf thnben bear. is related to the strengthened forms. The reinforcement effect of the lateral FRP wound in the compression zone is the best, but little effect is found along the longitudinal FRP.