干燥过程中马尾松板材干燥应变的研究.PDFVIP

第 28 卷第 4 期 南 京 林业大 学学 报( 自 然科 学 版) Vo l. 28 ,No .4 2004 年 7 月 Jomnal of Nanjing For臼try University( Natural Sciences Edition) Jul. , 2004 干燥过程中马尾松板材干燥应变的研究 涂登云，顾炼矿， 匾面屋，刘彬 (南京林业大学木材工业学院，江苏 南京 210037) 摘 要: 用木材干缩元件、弹簧和阻尼器构建马尾松板材干燥应变模型并采用改进的切片方法来分析干燥过 程中木材的自由干缩、瞬时弹性应变、新弹性应变和机械吸附应变的变化规律。在模型中引入与木材含水率 密切相关的干缩元件，解释各层的干缩差异是产生干燥应力的源动力。结果表明，勃弹性应变和弹性应变具 有相同的变化规律;机械吸附应变由应力和含水率变化共同作用产生，木材干燥结束后产生的机械吸附应变 是干燥各时期机械吸附应变的叠加;机械吸附应变的大部分在干燥前期产生。表层干缩差异达到最大的时间 可以作为判断干燥基准变更的时间 当表层干缩差异达最大值以后可以加快干燥速度。 关键词: 马尾松; 干燥应变;模型;机械吸附应变; 干缩差异 中图分类号 TS652 文献标识码:A 文章编号:1∞0- 2006(2∞4) 04- 0023- 06 A Study on Drying Strain of Pinus massoniana Lumber During D巧ring TU Den矿yun， GU Lian- bai* , [DU G旷xmg[ ， LIU Bin (College of Wood Science and Technology Nanjing Foreslly University, Nanjing 210037 , China) Abstract: A drying strain model of Pinus mωson~αna lumber ∞nsisting of wood shrinkage element , spring and damper and improved the traditional slicing method was developed in the paper to analyse the free shrinkage , instant elastic strain , visαT elastic strain and mechanσsorptive strain developed in wood chγmg. Wood drying shrinkage element introduced in the model may explain the original force of producing drying stress of shrinkage differential of different layers. 飞T iscσelastic strain had the same developed 1即 as an m- stant elastic strain. Mechanσsorptive strain was produced by the common function between stress and MC. Mechanσsorptive strain produced after the end of timber dηT ing was the summation of mechanσsorptive strain during the drying. A majority of mechanσsorptive strain was produced at the prophas