对具有纵向贯穿裂缝圆截面木梁全贴纤维增强聚合物(fiber reinforced polymer, FRP) 布的弯曲加固效果进行了研究. 在组合梁小挠度变形的假定下, 建立了全贴FRP 布加固带纵向贯穿裂缝圆截面木梁弯曲变形的控制方程, 研究了自由端集中载荷作用下FRP 布加固圆木梁的弯曲行为, 并得到了问题的解析解, 分析了FRP 布模量和厚度、梁长细比以及裂缝宽度等因素对FRP 布加固木梁弯曲变形的影响. 数值结果表明, FRP 布加固木梁自由端挠度随FRP 布厚度、弹性模量和剪切模量的增加而减少, 且当FRP 布厚度和弹性模量增加到一定值时, 继续增加其厚度和弹性模量对圆木梁的加固作用已不明显; FRP 布的剪切模量对短粗木梁挠度的影响较大, 且当剪切模量较大时, FRP 布加固可完全消除裂缝因素的影响.
The reinforcement effect of the fiber reinforced polymer (FRP) sheet bonding on the whole surface of a circular cross-section timber beam on the bending of timber beam with longitudinal through split is investigated. The governing equation for bending deformation of the circular timber beam with longitudinal split strengthened FRP sheet is established. The bending behavior of the FRP-strengthened circular timber beam under a concentrated load at its free end is studied. An analytical solution is obtained. Influences of the modulus and thickness of the FRP-sheet, slenderness ratio and split width of the timber beam, etc., on the bending behavior of the timber beam are analyzed. Numerical results show that the deflection of the FRP-strengthened circular timber beam at its free end is decreased with the increasing thickness, elastic and shear modulus of FRP sheet. When the modulus and thickness of the FRP sheet reach a certain values, the reinforcement effect is not obvious for continuing increase of the thickness and elastic modulus of the PRP sheet. Furthermore, the shear modulus of the FRP sheet has clear influence on the deflection of the short timber beam. The influence of beam’s split can be eliminated completely by the carbon FRP reinforcement when the shear modulus of the FRP sheet is large.
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