中文摘要：

通过对水热-微波联合处理的水曲柳幼龄材和成熟材顺纹压缩过程中应力-应变关系和木材化学组分变化的分析,建立木材顺纹压缩应力-应变本构关系。结果表明：在水曲柳顺纹压缩的初始阶段,应力-应变符合线性的弹性虎克定律;在弹塑性阶段,也基本符合线性的力学关系,建立的水曲柳幼龄材和成熟材顺纹压缩应力-应变本构关系由常数项（比例极限应力）和应力-应变线性关系表达式两部分构成;相同顺纹压缩率下幼龄材弹性模量和应力大于成熟材,主要受到木材化学组分差异的影响。

英文摘要：

Stress-strain relationship of longitudinal compressed hydrothermal-microwave treated juvenile and mature northeast China ash wood and their chemical composition variation were analyzed. The stress-strain constitutive relation of longitudinal compressed wood were established. Results showed that at the beginning of compression, the curves fol- lowed the linear Hooke＇s Law. Meanwhile, the curves primarily fit the linear mechanics relation at the elastic-plastic re- gion. The founded stress-strain constitutive relation showed that both juvenile and mature wood longitudinal compression could be expressed by an equation consisting of a constant term （proportional ultimate stress） and stress-strain linear re- lationship. The higher modulus of elasticity （MOE） and stress of juvenile wood was caused mainly by the difference of wood components between juvenile and mature ash wood at the same longitudinal compression rate.