Fatigue of structural plywood under cyclic shear through thickness III: energy dissipation performance

• Published in: Journal of wood science Vol. 54; no. 2; pp. 169 - 173
• Main Authors: Sugimoto, Takanori, Sasaki, Yasutoshi
• Format: Journal Article
• Language: English
• Published: Tokyo Japan : Springer Japan 01.04.2008; Springer Japan; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Characterization and Evaluation of Materials; Cyclic loads; Energy dissipation; Energy dissipation performance; Fatigue tests; Hysteresis loops; Life Sciences; Loading frequency; Loading waveform; Materials fatigue; Materials Science; Plywood; Shear; Shear through thickness; Strain; Stress-strain relationships; Thickness; Viscoelasticity; Wood composites; Wood Science & Technology; Energy dissipation performance; Loading waveform; Loading frequency; Shear through thickness; Plywood
• ISSN: 1435-0211; 1611-4663
• DOI: 10.1007/s10086-007-0929-1

Wood and wood composites have viscoelasticity, and show a hysteresis loop in the stress-strain relationship during cyclic loading such that part of the mechanical work applied is dissipated in the materials. In this study, the energy dissipation performance of plywood specimens under cyclic shear through thickness was investigated. Fatigue testing was conducted under three loading conditions: a square waveform at a loading frequency of 0.5 Hz, a triangular waveform at 0.5 Hz, and a triangular waveform at 5.0 Hz. The stress level was determined to be 0.5, 0.7, and 0.9 of the static strength in shear through thickness. The energy dissipation ratio was defined as the ratio of energy loss per cycle to the strain energy per cycle, and was evaluated throughout the fatigue test. It was found that the energy dissipation ratio of a plywood specimen was kept constant during most of the fatigue process for a given stress level and loading condition. The energy dissipation performance was significantly dependent on stress level and loading condition, and became higher according to the damage intensity of cyclic load even if the same strain energy was applied.