1.生物质材料科学与技术教育部重点实验室（东北林业大学），黑龙江哈尔滨 150040
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段云佳,卢昊,蔡英春等.基于数字图像相关技术的蒙古栎锯材干燥端面应变规律研究[J].木材科学与技术,2022,36(03):58-64.
DUAN Yun-jia,LU Hao,CAI Ying-chun,et al.Study on the Drying Strain of Cross-Section of Quercus mongolica Lumber Based on DIC Technique[J].Chinese Journal of Wood Science and Technology,2022,36(03):58-64.
以20 mm厚蒙古栎锯材为研究对象，采用数字图像相关（digital image correlation，DIC）技术实时监测其端面干燥过程中宽度（弦向）、厚度（径向）方向应变的分布，并分析干燥温度对宽度、厚度方向应变的影响。结果表明：在相同含水率的条件下，随着干燥温度的升高，沿厚度与宽度方向各层应变增大。中间与两侧部位之间应变差值，在40 ℃时为0.042，80 ℃时提高到0.059。锯材厚度方向应变数值增长趋势均相近，因此得出锯材干缩异向性的差异主要来自于锯材的宽度方向；40 ℃下锯材的干缩异向性数值大于80 ℃时的干缩异向性数值。DIC技术是非接触式检测木材干燥应变的有效手段，形变分布与传统检测手段结果相符，同时还可将干燥形变过程可视化。
To analyze the stress-strain law and shrinkage difference during the drying process, the strain profile of 20 mm thick ,Quercus mongolica, lumber along the width and thickness directions was monitored respectively by the digital image correlation (DIC) technique. This research analyzed the difference of drying strains in width and thickness directions and the effect of the temperature. The results indicated that the DIC was an effective non-contacted method of detecting the drying strain in wood. The DIC can visualize the drying deformation process while the results obtained by DIC was consistent with those of traditional detection methods. Meanwhile, under the condition of the same moisture content, the strain of each layer along the thickness and width directions increased progressively as the temperature increased. At the temperature of 80 °C, the difference of strain between the middle position and both sides were 0.059; whereas at the temperature of 40 °C, the difference decreased to 0.042. The strain values and trends along the thickness direction of ,Quercus mongolica, lumber were similar with those along the width direction. The wood shrinkage anisotropy was mainly derived from the width direction. Meanwhile, the value of wood shrinkage anisotropy was greater at 40 ℃ than at 80 ℃.
干燥应变数字图像相关技术含水率分布
drying straindigital image correlation(DIC) techniquesmoisture content distribution
李维桔. 木材弹性及木材干燥应力——Ⅱ、木材干燥应力[J]. 南京林业大学学报(自然科学版), 1983(2): 107-122.
FU Z, ZHAO J, HUAN S, et al. The variation of tangential rheological properties caused by shrinkage anisotropy and moisture content gradient in white birch disks[J]. Holzforschung, 2015, 69(5): 573-579.
Mcmillen J M. Dry stresses in red oak[J]. Forest Product Journal, 1958, 5(1):71-76.
蒋佳荔, 吕建雄. 木材干燥应力的研究方法与进展[J]. 木材工业, 2005, 19(2): 4-7, 16.
JIANG J L, LU J X. Review of research methods for wood drying stresses[J]. China Wood Industry, 2005, 19(2): 4-7, 16.
Skaar C, Simpson W T, Honeycutt R M. Use of acoustic emissions to identify high levels of stress during oak lumber drying[J]. Forest Products Journal, 1980, 30(2): 21-22.
Khoo S W, Karuppanan S, Tan C S. A review of surface deformation and strain measurement using two-dimensional digital image correlation[J]. Metrology and Measurement Systems, 2016, 23(3):461-480.
Peters W H, Ranson W F, Sutton M A, et al. Application of digital correlation methods to rigid body mechanics[J]. Optical Engineering, 1983, 22(6): 738-742.
Kifetew G. Application of the deformation field measurement method to wood during drying[J].Wood Science and Technology, 1996, 30(6): 455-462.
PENG M, HO Y C, WANG W C, et al. Measurement of wood shrinkage in jack pine using three dimensional digital image correlation (DIC)[J]. Holzforschung, 2012, 66(5): 639-643.
Gauvin C, Jullien D, Doumalin P, et al. Image correlation to evaluate the influence of hygrothermal loading on wood[J]. Strain, 2014, 50(5): 428-435.
Kang C W, Muszyński L, Hong S H, et al. Preliminary tests for the application of an optical measurement system for the development of a kiln-drying schedule[J]. Drying Technology, 2016, 34(4): 483-490.
Mallet J, Kalyanasundaram S, Evans P D. Digital image correlation of strains at profiled wood surfaces exposed to wetting and drying[J]. Journal of Imaging, 2018, 4(2): 38.
Larsen F, Ormarsson S. Experimental and finite element study of the effect of temperature and moisture on the tangential tensile strength and fracture behavior in timber logs[J]. Holzforschung, 2014, 68(1): 133-140.
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