Original paper(Vol.48 No.3 pp.240)

Low Cycle Fatigue Test of LVL@under Longitudinal Compression

Naruse Katsufusa; Yoshida Akihiro; Nashihara Hiroshi; Shizukuishi Katsuzou; Motoki Yuuji

Abstract:To examine the low cycle fatigue properties of laminated beech (Fagus crenata Bl.), compression-compression tests are carried out at high loading levels in the direction parallel to wood grain. A test specimen has shallow notches in order to avoid the die test piece interface fractures. The notch effect on the static stress distribution is analyzed by a three dimensional FEM. Upper limit load is given by assigning the increment of strain from basic stress state and load amplitude remains unchanged through the tests. Experimental results show that the critical number of cycles to fracture becomes smaller with increasing magnitudes of the strain increment, although the scatter of its values is observed to some extent. Furthermore, it is found that typical fracturing pattern is the type of a inclined straight line originating from the root of a groove.

Key Words:low cycle fatigue, molded plywood, compression-compression fatigue, small notch, simple compression, 3D FEM analysis, fracture mode