林业工程学报2025，Vol.10Issue(4)：19-27,9.DOI:10.13360/j.issn.2096-1359.202503008
重组竹高温处理后的Ⅰ型断裂力学特性
Mode Ⅰ fracture behavior of bamboo scrimber following high-temperature treatment
摘要
Abstract
Bamboo scrimber materials are characterized by the presence of micro-cracks and interlayer voids within their structure.When exposed to high temperatures and subjected to dynamic loading,they are prone to fracture,which can significantly compromise their structural performance and reliability.This study investigated the transverse mode Ⅰdynamic fracture toughness of bamboo scrimber using notched semi-circular bend(NSCB)specimens under three-point bending fracture tests.Three dimensionless crack lengths(0.4,0.5,and 0.6),five moisture content levels(4％,8％,10％,12％,and 16％),and six temperature conditions(20,80,130,180,230,and 280 ℃)were selected as experimental parameters.To compare the influence of loading rate on the mode Ⅰ fracture toughness of bamboo scrimber under dynamic loading conditions,a split Hopkinson pressure bar(SHPB)was utilized to control air pressure and achieve three distinct loading speeds,with impact velocities of 6,7,and 8 m/s.This enabled a comprehensive analysis of how fracture toughness is influenced by temperature,moisture content,and impact velocity.An influence coefficient formula was also proposed to model these relationships.The experimental results revealed that the dynamic initiation fractured toughness of bamboo scrimber in transverse mode Ⅰ,under the same dimensionless crack lengths and impact velocities,followed trends like those observed under quasi-static loading conditions.As the moisture content increased from 4％to 16％,the fracture toughness initially increased and then decreased,peaking at a moisture content of 10％.Additionally,as the temperature increased from 20 to 280 ℃,the fracture toughness gradually decreased.Notably,after reaching 180 ℃,a more pronounced decrease in fracturing toughness was observed in some of the specimens.Furthermore,the dynamic fracture toughness showed a positive correlation with impact velocity,suggesting enhanced crack resistance under higher loading rates.These findings highlighted the critical role of moisture content,temperature,and loading rate in governing the fracture behavior of bamboo scrimber.The degradation mechanism at elevated temperatures involved the thermal decomposition of cellulose and hemicellulose,which compromised the interfacial bonding between bamboo fibers.The non-monotonic relationship between moisture content and fractured toughness reflected the competing effects of moisture-induced plasticization and stress concentration caused by uneven swelling.The derived influence coefficient formula integrated these factors,providing a predictive tool for evaluating the fracture performance of bamboo scrimber in practical engineering scenarios.This research established a theoretical foundation for optimizing the structural design and safety assessment of bamboo scrimber in high-temperature and dynamic loading environments.The outcomes contribute to the development of material-specific standards,supporting the wider adoption of bamboo scrimber in sustainable construction and engineering applications.关键词
重组竹/霍普金森压杆(SHPB)/Ⅰ型/断裂韧度/高温处理Key words
bamboo scrimber/split Hopkinson pressure bar(SHPB)/mode Ⅰ/fracture toughness/high-temperature treatment分类
农业科技引用本文复制引用
吴前煌,郭任坤,郭楠,饶久平,杨文斌,盛叶..重组竹高温处理后的Ⅰ型断裂力学特性[J].林业工程学报,2025,10(4):19-27,9.基金项目
福建省科技厅国家科技项目备案类(2023L3046) （2023L3046）
中建股份科技研发项目(CSCEC-2022-Z-58) （CSCEC-2022-Z-58）
福建省科技计划项目星火项目(2022S0029). （2022S0029）
