林业工程学报2024，Vol.9Issue(6)：20-26,7.DOI:10.13360/j.issn.2096-1359.202404015
含水率对重组竹静态和动态横纹冲击力学性能的影响
Effect of moisture content on the static and dynamic impact properties of bamboo scrimber perpendicular to grain
摘要
Abstract
Bamboo scrimber is a new type of biomass composite material that exhibits superior mechanical properties compared to wood like larch and can be easily processed into structural components such as beams and columns.While extensive research has been conducted on the static mechanical properties of bamboo scrimber,studies focusing on its behavior under dynamic loading conditions remain limited.In extreme environments,such as hailstorms,typhoons with debris,or impacts from external objects,materials may experience significant dynamic loads that can cause intense dynamic responses,potentially leading to cracking or failure of the bamboo scrimber,thus affecting the safety and longevity of the entire structure.Therefore,it is essential to analyze the dynamic response of the material to understand its mechanical performance under dynamic loads.Given that the compressive direction of bamboo scrimber columns in buildings is typically parallel to the grain,they mainly endure impacts perpendicular to the grain when subjected to horizontal impact loads.This study investigated bamboo scrimber with an average density of 1.13 g/cm3,conducting static uniaxial compression tests at various moisture contents(4％,8％,10％,12％and 16％)as a baseline.Additionally,dynamic impact tests were performed on bamboo scrimber at the same moisture contents and different impact velocities(10,13 and 16 m/s),using a split Hopkinson pressure bar(SHPB)apparatus.The results indicated that the static compressive strength and elastic modulus of bamboo scrimber perpendicular to the grain decreased with increasing moisture content.Under dynamic loading conditions,the dynamic compressive strength of bamboo scrimber perpendicular to the grain significantly increased with the impact velocity(loading rate)while the moisture content remained constant.This increase ranged from 2.39 times of the static loading to 5.63 times,with the rate of increase gradually slowing.The impact velocity had a minimal effect on the elastic modulus.When the impact velocity remained constant,both the dynamic compressive strength and elastic modulus of bamboo scrimber perpendicular to the grain decreased gradually as the moisture content increased from 4％to 16％.By fitting the dynamic increase factor(DIF)and the ratio of static to dynamic elastic modulus,this study derived formulas that described the effects of moisture content and loading rate on the impact mechanical properties of bamboo scrimber perpendicular to the grain.These findings provide a theoretical basis for establishing a constitutive model of bamboo scrimber under impact loads.关键词
重组竹/冲击性能/含水率/加载率/动力放大系数Key words
bamboo scrimber/impact property/moisture content/loading rate/dynamic increasing factor(DIF)分类
农业科技引用本文复制引用
盛叶,张鸣轩,张峰,谢智锐,郭任坤,郭楠..含水率对重组竹静态和动态横纹冲击力学性能的影响[J].林业工程学报,2024,9(6):20-26,7.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）
