改性亚麻纤维增强胶合木梁受弯性能试验  

Flexural Behavior of Modified Flax Fiber Reinforced Polymer Reinforced Glulam Beams

作　　者：左宏亮[1] 王照稳 李熠诗 Zuo Hongliang;Wang Zhaowen;Li Yishi(Northeast Forestry University,Harbin 150040,P.R.China)

机构地区：[1]东北林业大学土木工程学院,哈尔滨150040 [2]东北林业大学,哈尔滨150040

出　　处：《东北林业大学学报》2021年第4期76-80,共5页Journal of Northeast Forestry University

基　　金：黑龙江省自然科学基金项目(LH2020E009)。

摘　　要：将天然亚麻纤维经纳米TiO2接枝制得改性亚麻纤维复合材料(FFRP),以云杉-松树-冷杉木板(SPF木板)为原材料制作24根尺寸为2 850 mm×50 mm×150 mm的胶合木梁试件,采用改性亚麻纤维复合材料通过顺向粘贴在梁底部、横向粘贴在梁侧面和底部(U型箍)的方式对胶合木梁进行增强。对8组试件进行三分点加载受弯试验,分析梁底部改性亚麻纤维复合材料粘贴方式(粘贴长度、粘贴层数、U型箍)对胶合木梁破坏形态、极限承载力、跨中挠度、截面应变的影响及粘贴FFRP对胶合木梁受弯性能的增强效果。结果表明:在不发生剥离破坏的前提下,底部粘贴长度对胶合木梁的抗弯性能影响不大。对于无箍胶合木梁,底部粘贴FFRP能够提高胶合木梁的抗弯承载力与刚度,但底部粘贴的层数不宜过多,粘贴层数过多反而会导致提高幅度有所下降;对于有箍胶合木梁,其抗弯承载力与抗弯刚度,均随着底部粘贴FFRP层数的增加而增大。当底部粘贴3层FFRP时,有箍和无箍胶合木梁的抗弯承载力与抗弯刚度相差不大,但有箍梁的延性得到明显提高;当底部粘贴6层FFRP时,有箍梁的抗弯承载力和抗弯刚度比无箍梁均有明显提高。U型箍可以改变胶合木梁的破坏形态,无箍胶合木梁的破坏形态同普通梁一样,为脆性破坏;而有箍梁的破坏形态为延性破坏,U型箍能够避免木材层板间开裂与横向撕裂,增强FFRP与梁底部木材的协调性能,提高胶合木梁的抗弯性能。The modified flax fiber composite material-FFRP(Flax Fiber Reinforced Polymer/Plastic) was prepared by grafting natural flax fiber with nano-TiO2. Using SPF(Spruce-Pine-Fir) as raw materials, 24 glulam beam specimens with dimensions of 2 850 mm×50 mm×150 mm were made. The modified flax fiber material strengthens the glulam beam by pasting it on the bottom of the beam along the length of the beam and on the side and bottom of the beam along the width of the beam(U-shaped hoops). A three-point load bending test was carried out on 8 sets of specimens, and the influence of the bonding length(interface bonding performance), the number of pasting layers and U-shaped hoops at the bottom of the beam on the failure form, ultimate bearing capacity, mid-span deflection and section strain of the glulam beam was analyzed. Laws, study the enhancement effect of FFRP on the bending performance of glulam beams. The test results show that under the premise of no peeling failure, the bottom bonding length has little effect on the bending resistance of the glulam beam. For non-hoop glulam beams, FFRP pasting at the bottom of beams can improve the flexural bearing capacity and rigidity of the glulam beams, but the number of pasting layers should not be too large. If the number of pasting layers is too large, the good effect on the flexural bearing capacity and the flexural rigidity will be weakened. For the hoop glulam beam, its flexural bearing capacity and flexural rigidity increased with the increase of the number of layers FFRP pasted on the bottom. When 3 layers of FFRP were pasted on the bottom of beams, the flexural bearing capacity and flexural rigidity of hoop and non-hoop glulam beams were not much different, but the ductility of hoop beams was significantly improved;when 6 layers of FFRP were pasted on the bottom of beams, the flexural bearing capacity and flexural rigidity of beams with hoops were significantly improved compared with beams without hoops. U-shaped hoops can change the failure form of glulam beams. The fa

关 键 词：胶合木梁 受弯性能 改性亚麻纤维 

分 类 号：S781.2[农业科学—木材科学与技术] TU366.3[农业科学—林学]