热压过程竹材的径向应变特性  

Properties of radial strain of bamboo in the process of hot pressing

作　　者：韩健[1] 高喜桃[1] 

机构地区：[1]中南林业科技大学材料科学与工程学院,湖南长沙410004

出　　处：《中南林业科技大学学报》2010年第8期96-99,共4页Journal of Central South University of Forestry & Technology

基　　金：科技部支撑计划项目资金资助"太阳能圆竹预制房屋关键构件制造技术研究与示范"(项目编号:2008BADA9B0202)

摘　　要：竹材的径向应变直接影响到很多竹产品的表面平整度和厚度公差。通过采用动态电阻应变仪对热压不同阶段竹材的径向应变进行检测,表明在压力和温度的共同作用下,在升温阶段,竹材的径向应变经历了由小变大,再由大变小的过程。在保温降压阶段,随压力降低竹材产生径向回弹,径向应变逐渐减小,当压力降到零时,竹材仍保持一定的负应变。在卸压后的自然冷却过程中,随冷却时间延长竹材径向应变呈增加趋势,温差越大,负应变越大。在热压过程的各阶段,在相同压力和温度条件下,不同试样应变值存在较大差异。The radial strain of bamboo wood affects directly the surface smoothness and thickness deviation of many bamboo products.The dynamic resistance strain instrument was used for testing the bamboo radial strain at different stages in the process of hot-pressing.By the action of pressure and temperature,the radial strain of bamboo changed from being minor to being major again from being major to being minor at the heating up stage.Bamboo caused radial rebounding,radial strain gradually reduced with pressure lowering,and bamboo still remained some strain when the pressure reduced to zero at heat preservation-unload stage.The radial strain of bamboo gradually increased as time extending,and the bigger the difference in temperature,the bigger the negative strain at naturally cooling stage.At each stage of hot-pressing,the strains of different test specimens had great differences at the same pressure and temperature.

关 键 词：木材科学 竹材 热压 径向应变 特性 

分 类 号：S781.2[农业科学—木材科学与技术]