干燥过程中马尾松板材干燥应变的研究

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、黏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，黏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馊。

A Study on Drying Strain of Pinus massoniana Lumber During Drying

A drying strain model of Pinus massoniana lumber consisting 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,visco-elastic strain and mechano-sorptive strain developed in wood drying.Wood drying shrinkage element introduced in the model may explain the original force of producing drying stress of shrinkage differential of different layers.Visco-elastic strain had the same developed law as an instant elastic strain.Mechano-sorptive strain was produced by the common function between stress and MC.Mechano-sorptive strain produced after the end of timber drying was the summation of mechano-sorptive strain during the drying.A majority of mechano-sorptive strain was produced at the prophase of drying.The time of biggest differential of surface shrinkage reached can be used as the time of judging the alteration of the drying schedule,afterwards the drying schedule can be accelerated.