A Study of Wood Physical and Mechanical Properties and Vertical Variation Characteristics of Natural Liriodendron chinense Forest

Key words: 
• Liriodendron chinense /
• Natural forest /
• Wood physical property /
• Wood mechanical property /
• Vertical variation

Abstract: Studies were made of the physical and mechanical properties and its vertical variation of Liriodendron chinense wood from natural forest.The results showed the wood basic density(BD),over-dry density(DD)and air-dry density(AD)were respectively 0.352 g·cm^-3,0.396 g·cm^-3 and 0.558 g·cm^-3.The characteristics of BD,DD and AD displayed the upper > middle > lower parts in the vertical direction,and the difference was very significant.The wood volume shrinkage ratio of natural L.chinense forest under air-drying condition were 7.21%,while under oven-dry condition,it was 2.54%.The wet expansion rate of wood volume was 4.54% from oven-dry to air-dry,while the volume wet expansion rate of wood was 12.41% from air-dry to water absorption.The wood shrinkage was the upper > the lower > the middle part in the vertical direction,while the volume wetting rate was the the upper part > the middle part > the lower part.The volume dry shrinkage dampness was different in the vertical direction.The compressive strength and flexural strength of the wood were 34.7 MPa and 53.22 MPa,respectively.The hardness of the transverse,chord and diameter surfaces were 3.49 kN,2.55 kN and 2.45 kN,respectively.In the vertical direction,the CIS compressive strength,bending strength,transverse hardness and the hardness of the diameter surface of wood showed the rule of the upper part > the middle part > the lower part.It was proved that wood density of natural forest of L. chinense was a light medium level,and its CIS compression,bending resistance and hardness were general level.The wood of L. chinense was suitable for processing and utilization.