表面强化刨切薄板拉伸、弯曲性能

以黑龙江产大青杨刨切薄板为研究对象,用常温水浸泡至饱水状态,不经热软化预处理即进行横纹压缩强化,通过160、180℃高温定型处理1～24 h,分析横纹压缩强化前、后木材的拉伸、弯曲性能的变化,探讨此方法强化木材薄板的可行性和有待改进、完善之处。结果表明:与未压缩强化素材相比,木材的拉伸强度和拉伸弹性模量均有较大幅度提高;弯曲弹性模量随着热处理时间的增加而下降;弯曲强度和断裂应力有所降低;最大应力时应变平均值、断裂应力时应变平均值都随着热处理时间的增加而下降。

Tensile and Bending Properties of Surface Strengthened Sliced Wood Sheets

Sliced wood sheets of Populus ussuriensis were dipped in water under normal temperature until water-saturated,then were compressed perpendicular to grain without heat softening pretreatment.Tensile and bending properties of the wood sheets after hot compression and fixation for 1~24 h under 160 or 180 degrees C were analyzed before and after compre-ssion in order to probe the feasibility of this strengthening method of wood sheets.Results show that the tensile strength and tensile elastic modulus of the wood are greatly improved compared to the uncompressed strengthened material.The bending elastic modulus decreases with increasing heat treatment duration.The bending strength and fracture stress are both substantially reduced compared to the uncompressed strengthened material.The average strain at maximum stress and the average strain at fracture stress both decrease with increasing heat treatment duration.