Initial shapes of stress-strain curve of wood specimen subjected to repeated combined compression and vibration stresses and the piezoelectric behavior

Takahisa Nakai, Hiroyuki Yamamoto, Masatoshi Hamatake, Tetsuya Nakao

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6 Citations (Scopus)

Abstract

This study investigated the relationship between the initial shape of the stress (σ)-strain (ε) curve of a Chamaecyparis obtusa wood specimen subjected to repeated combined compression and vibration stresses at various angles between the fiber direction and load direction and the piezoelectric behavior. The main findings of the study are: (1) the σ-ε curve became convex initially, and then the stress was proportional to the strain. The σ-ε curve had almost the same shape during both loading and unloading. (2) The σ-piezoelectric voltage (P) curve was nonlinear, with a maximal point or cusp on the curve, which had almost the same shape during both loading and unloading, as was also observed for the σ-ε curve. (3) The plot of the first derivative of the stress [dσ/dε (= σ′)] against ε was nonlinear. The σ′-ε and P-ε curves at various angles were fairly similar. (4) The stress at the maximal point (or cusp) of the σ-P curve decreased with an increase in the angle between the fiber direction and load direction. The tendency of the stresses was very similar to that of Young's modulus and compression strength calculated from Hook's law and Hankinson's law, respectively.

Original languageEnglish
Pages (from-to)539-543
Number of pages5
JournalJournal of Wood Science
Volume52
Issue number6
DOIs
Publication statusPublished - Dec 1 2006
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Biomaterials

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