集中载荷作用下FRP布加固带裂缝木梁的弯曲  

Bending of Split Timber Beam Strengthened with Fiber Reinforced Polymer Under Concentrated Load

作　　者：吴郦威[1] 欧阳煜[1] 杨骁[1] 董雪婷[1] 

机构地区：[1]上海大学土木工程系,上海2000721

出　　处：《力学季刊》2013年第3期367-376,共10页Chinese Quarterly of Mechanics

基　　金：国家高技术研究发展计划(2009AA032303-2)

摘　　要：将FRP布视为正交各向异性材料,考虑其拉伸与压缩时的双弹性模量性质,给出了四周粘贴FRP布加固带裂缝木梁四点弯曲的边值问题,得到了FRP布加固木梁挠度的解析解,并验证了其有效性和适用性。参数分析表明:相比于侧面粘贴CFRP布,在木梁受拉侧沿轴向粘贴CFRP布的刚度加固效果更加显著;CFRP布加固木梁的挠度随CFRP加固布厚度和弹性模量的增加而减小,但当侧贴CFRP布厚度增加到某一值时,继续增加厚度对木梁挠度的减少效果已不明显;当受拉侧CFRP布厚度较小时,木梁挠度随CFRP布厚度的增加非线性减小,而当受拉侧CFRP布厚度较大时,木梁挠度随CFRP布厚度几乎呈线性减小。同时,当侧贴CFRP布的剪切模量很大时,此时,CFRP布加固带裂缝木梁的挠度趋于CFRP布加固完整无裂缝木梁的挠度,此时,CFRP加固完全消除了裂缝因素。Regarding the FRP sheet as an orthotropic material and considering its bi-modulus for tension and compression, the boundary value problem for four-point bending of the timber beam with longitudinal through split strengthened with FRP sheet by around bonding was presented. The analytical solution of the deflection of the FRP-strengthened timber beam was obtained, and its validity and applicability were verified. It is shown from the parameter study that the reinforcement effect for stiffness of the timber beam by axial bonding CFRP sheet on its tension side is more significant than that by lateral bonding CFRP sheet. The deflections of the FRP-strengthened timber beam are decreased with the thickness and elastic modulus of the CFRP sheet increasing, and when the thickness of the CFRP sheet for lateral bonding rea- ches to a certain value, the effect of the deflection decreasing by increasing the thickness of the CFRP sheet is unnoticeable. For smaller thickness of FRP sheet on the tension side, the deflection of the timber beam is decreased nonlinearly with the thickness of the CFRP sheet increasing, while for larger thickness of FRP sheet on the tension side, the deflection of the timber beam is almost linearly decreased with the thickness of the CFRP sheet increasing. Furthermore, when the shear modulus of the FRP sheet for lateral bonding is very large, the deflections of the split timber beam strengthened with FRP sheet converge to those of the complete timber beam strengthened with FRP sheet, and the influence of the split is eliminated completely by the CFRP reinforcement.

关 键 词：纤维增强复合材料 带裂缝矩形木梁 加固修复 弯曲 

分 类 号：O343.9[理学—固体力学] TU366.2[理学—力学]