The strength and rigidity of joints in wooden ships depend, first of all, on the bearing strength of wood under compression.
In this paper, the bearing strength of wood under compression and also the apparent modulus of compression E' are investigated considering the fine structure of wood. Structural calculations are made on the assumed models of fine structures of wood and show satisfactory coincidence with the anisotropic behavior of Young's modulus and the bearing strength of wood.
The “tracheid” simulated models, which are made up of laminated paper, are tested under compression and fairy explains the state of contact surface. From these model experiments, it is explained that due to the local collapse of fine structures which are ruined about 1-3 mm from the surface by sawing and reduced to 1/10-1/15 in the rigidity under compression, the apparent modulus of compression E' become smaller than Young's modulus of compression E. And the anisotropic behavior of Young's modulus are also well explainable with the above assumption of fine structure of wood.