文献类型：期刊文献

中文题名：木材压缩吸能特性的尺寸与形状效应

英文题名：Size and shape effects of wood compression energy absorption characteristics

作者：孔静[1] 吕文华[1] 徐诗雨[1] 杨志一[1]

第一作者：孔静

机构：[1]中国林业科学研究院木材工业研究所,北京100091

年份：2023

卷号：45

期号：11

起止页码：152-160

中文期刊名：北京林业大学学报

外文期刊名：Journal of Beijing Forestry University

收录：CSTPCD;;北大核心:【北大核心2020】；CSCD:【CSCD2023_2024】；

基金：中央级公益性科研院所基本科研业务费专项(CAFYBB2022MA001)。

语种：中文

中文关键词：准静态大变形压缩;木材压缩;应力–应变曲线;尺寸效应;形状效应;吸能特性

外文关键词：quasi-static large deformation compression;wood compression;stress-strain curve;size effect;shape effect;energy absorption performance

分类号：S781;S791.29

摘要：【目的】解析试样尺寸和形状对木材压缩吸能特性的影响,指导木材压缩吸能特性的科学测试和评价。【方法】通过准静态大变形压缩试验,分别考察了毛白杨、杉木、泡桐和轻木4种木材,在不同截面尺寸(20 mm×20 mm、50 mm×50 mm)、不同截面形状(圆形Φ20 mm、方形20 mm×20 mm)下的压缩力学响应和吸能特性,并通过t检验分析其差异显著性。【结果】(1)木材“三段式”压缩应力–应变曲线不受试样尺寸和形状影响。(2)木材顺纹压缩破坏强度尺寸效应显著,强度随试样尺寸增大而减小,泡桐和轻木的顺纹压缩强度由小尺寸试样的30.94和14.56 MPa,分别减小至大尺寸试样的26.06和13.37 MPa,尺寸效应系数分别为0.84和0.92;木材横纹压缩强度、顺纹和横纹的破坏特征与吸能特性无明显尺寸效应。(3)木材顺纹压缩强度形状效应显著,圆形试样强度低于方形试样,形状效应系数为0.88~0.93;木材压缩破坏特征和吸能特性的形状效应与树种特性相关,杉木、泡桐和轻木的破坏模式以及吸能特性均不受形状影响;毛白杨吸能性能形状效应显著,圆形试样吸能性能优于方形试样。(4)木材密度越大,其尺寸和形状效应越明显。【结论】低密度轻软木材的吸能特性无尺寸和形状效应,建议采用取材易、加工简便、耗材少、成本低的小尺寸方形试样进行压缩吸能测评。
[Objective]The research aimed to investigate the influence of specimen size and shape on wood compression energy absorption characteristics and guide the scientific test and evaluation of wood compression energy absorption properties.[Method]Through a quasi-static large deformation compression test,the compressive response and energy absorption characteristics of Populus tomentosa,Chinese fir,paulownia and balsa wood under the different cross-sectional dimensions(20 mm×20 mm,50 mm×50 mm),different cross-sectional shapes(20 mm round and 20 mm×20 mm square)were investigated,and analyzed by t-test.[Result](1)The stress-strain curve of wood under compression was unaffected by specimen size and shape,following a“three-stage”pattern.(2)The size effect of wood compressive crushing strength along grain was significant,and the crushing strength decreased with the increase of specimen size.The crushing strength along the grain of paulownia and balsa wood decreased from 30.94 and 14.56 MPa for small-sized specimens to 26.06 and 13.37 MPa for large-sized specimens,and the size effect coefficients were 0.84 and 0.92,respectively.The transverse compressive strength,the failure mode and compressive energy absorption performance of wood along grain and cross grain were all not affected by specimen size.(3)The compressive crushing strength along the grain of wood had a significant shape effect.The compressive strength of four kinds wood along the grain of round specimens was smaller than that of square specimens,and the shape effect coefficient ranged from 0.88 to 0.93.The specimen shape effect of wood compression failure mode and energy absorption performance was related to tree species characteristics.The failure mode and energy absorption performance of Chinese fir,paulownia and balsa wood were not influenced by the specimen shape.The energy absorption performance of the round specimens of Populus tomentosa wood was significantly greater than those of the square specimens,which had an obvious shape effect.(4)The compressive strength of wood increased with an increase in wood density and compressive strength,with a more apparent size and shape effect.[Conclusion]The energy absorption characteristics of low-density wood have no size and shape effects,so it is recommended to use small-size square specimens with easy sampling,simple processing,fewer consumables and low cost for compression energy absorption evaluation.