林业工程学报2018，Vol.3Issue(3)：128-135,8.DOI:10.13360/j.issn.2096-1359.2018.03.021
碳纤维复合材料加固带缺陷木梁的试验研究
Study on carbon fiber reinforced polymer reinforced timber beams with defects
摘要
Abstract
Wood is one of biomass materials along with natural defects. In other words, there are not wood components without defects in the actual use, and most of the existing wood structures have to be built by using timber with imper-fections. Because mechanical properties are reduced due to the components with defects, the safety concerns of the wood structures have been increased in the building material market. To address the concerns, in recent years, the use of car-bon fiber reinforced polymer ( CFRP) in timber structure has been developed. The CFRP timber is regarded as an eco-nomic and effective material due to the enhanced strength and stiffness. The mechanical properties of timber members are different with different defects. The load-carrying capacity of the member can be increased by pasting CFRP in convex side of defective beams. Mechanical performances and failure mode of timber with and without the CFRP reinforcement were examined by 4-point bending experiments. The effect of different defect size and different positions on the failure mode and bearing capacity were analyzed. The test results showed that, no matter whether defects exist in timber, the failure process including elastic deformation, stiffness degradation and failure is nonlinear and progressive. The bending strength values of different failure types caused by the defects are lower than the theoretical values. Compared with the compressive zone, the defect effect on the bending strength in the tensile zone is much greater. The presence of defects in the neutral axis leads to a brittle failure of the timber. The results revealed that, when knots exist in the tension zone, using the CFRP to reinforce beams is highly effective. However, when the defects exist in compressive zone, even the CFRP is pasted at the bottom of beams, the final damage is determined by the defects damage and the reinforcement effect is not significant, which has little effect on reinforcing beams. The bearing capacity increased by using the CFRP to reinforce timber beams, and pasting two layers of the CFRP is better than pasting one layer.关键词
木梁/缺陷/力学性能/CFRP/加固Key words
timber beam/defect/mechanical performance/CFRP/reinforcement分类
建筑与水利引用本文复制引用
张露,周爱萍,盛宝璐,沈玉蓉,许嘉诺..碳纤维复合材料加固带缺陷木梁的试验研究[J].林业工程学报,2018,3(3):128-135,8.基金项目
国家自然科学基金(51578291) （51578291）
林业科学技术成果国家级推广项目([2015]21号). （[2015]21号）
