竹材非对称性弯曲行为对弯曲构件性能的影响  

Influence of asymmetric bending behavior of bamboo on performance of curved components

作　　者：李喆喆 施江靖 陈红 吴智慧 季加贵 胡永茂 Li Zhezhe;Shi Jiangjing;Chen Hong;Wu Zhihui;Ji Jiagui;Hu Yongmao(College of Furnishings and Industrial Design,Nanjing Forestry University,Nanjing 210037,Jiangsu,China;College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,Jiangsu,China;Zhejiang Sanjian Industry&Trade Co.,Ltd,Lishui 323800,Zhejiang,China)

机构地区：[1]南京林业大学家居与工业设计学院,江苏南京210037 [2]南京林业大学材料科学与工程学院,江苏南京210037 [3]浙江三箭工贸有限公司,浙江丽水323800

出　　处：《北京林业大学学报》2025年第4期168-176,共9页Journal of Beijing Forestry University

基　　金：浙江省博士后基金二等资助项目(ZJ2022170)。

摘　　要：【目的】竹材因其自身结构差异(如非对称性弯曲行为),在相同工艺条件下制备的弯曲构件品质不稳定。本研究旨在探索不同部位竹条在不同弯曲模式下的成型规律,以提高竹条弯曲构件制备的可控性,并为其工艺优化提供科学依据。【方法】采用一体式弯曲成型工艺,研究竹青侧受压(TypeⅠ)和竹黄侧受压(TypeⅡ)两种弯曲模式下,竹秆不同部位(基部、中部、梢部)竹条的弯曲性能以及弯曲构件的弯曲合格率、最小弯曲半径范围和弯曲稳定性。【结果】竹秆中部竹条的纤维体积分数最高,基部次之,梢部最低,且竹条的弯曲性能与纤维体积分数呈正相关。在相同部位,TypeⅠ模式下竹条的弯曲强度和模量高于TypeⅡ模式,但TypeⅡ模式下竹条的弯曲韧性更高。TypeⅡ模式更易于成功制备弯曲构件,并可实现更小的弯曲半径。相比基部与梢部,中部竹条制备的弯曲构件的弯曲合格率更高,中部竹条在TypeⅡ模式下的最小弯曲半径(R)范围为30 mm<R≤60 mm。弯曲构件的弯曲稳定性与竹条的纤维体积分数呈负相关,具有最高纤维体积分数的中部竹条弯曲构件回弹角最大。【结论】竹秆不同部位的竹条在径向弯曲载荷作用下表现出显著的非对称性弯曲行为。在制备竹条弯曲构件时,可根据所需弯曲程度选择合适的竹秆部位和弯曲模式。使用中部竹条并采用TypeⅡ模式,能够有效提高弯曲构件的合格率和性能稳定性,尤其适用于制备弯曲程度较高的构件。[Objective]The quality of curved components produced under identical process conditions exhibits instability due to the structural heterogeneity of bamboo,such as its asymmetric bending behavior.This study aimed to explore the forming regulations of bamboo strips derived from different parts of bamboo culms under varied bending modes,aiming to enhance the controllability of producing bamboo strip curved components and to provide a scientific foundation for process optimization.[Method]A one-piece bending forming process was employed to fabricate curved components.The bending properties of bamboo strips from different parts of bamboo culms were investigated under two bending modes,namely compression on bamboo outer layer(TypeⅠ)and compression on bamboo inner layer(TypeⅡ).Additionally,the bending pass rate,minimum bending radius range,and bending stability of curved components were also examined.[Result]The fiber volume fraction of bamboo strips was the highest in the middle part,followed by the root part,and the lowest in top part.Additionally,there was a positive correlation between bending properties of bamboo strips and their fiber volume fraction.For the same parts of bamboo culms,the bending strength and modulus of bamboo strips were higher under TypeⅠmode compared with those under TypeⅡmode,while bamboo strips under TypeⅡmode exhibited higher bending toughness.Bamboo strip curved components were more likely to be successfully bent and shaped when compressed under TypeⅡmode rather than TypeⅠmode,resulting in achieving smaller bending radii.The bending pass rate of curved components fabricated from the middle part of bamboo strips was higher compared with that of root and top part of bamboo strips,and the minimum bending radius of the middle part of bamboo strips was in the range of 30 mm<R≤60 mm when they were bent under TypeⅡmode.The bending stability of curved components was negatively correlated with fiber volume fraction of bamboo strips,and the middle bamboo strip curved components with

关 键 词：竹材 弯曲构件 非对称性弯曲行为 弯曲成型 纤维体积分数 弯曲稳定性 力学性能 结构特性 

分 类 号：S781.9[农业科学—木材科学与技术]