単板積層材エレメントの強度分布推定手法に関する有効性の検討(第<b>1</b>報):単板積層材強度における積層効果  [in Japanese] Validation of Method for Estimating Element Strength Distribution of Laminated Veneer Lumber I.:Laminating effect in the strength of laminated veneer lumber  [in Japanese]

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Author(s)

    • 小関 真琴 Koseki Makoto
    • 秋田県立大学木材高度加工研究所|公益財団法人日本合板検査会 Institute of Wood Technology, Akita Prefectural University|Japan Plywood Inspection Corporation

Abstract

既報では,単板積層材(LVL)のエレメントを接着層付きの単板と仮定し,積層数の異なるLVL強度データから,非線形最小二乗法によりエレメントの強度分布を推定する手法を提案した。しかし,推定した強度分布は実際の強度分布に適合するか検証していないことから,既報で用いたLVLの残部から接着層付きの1~3plyの試験体を切り出し,既報と同様の強度試験を行った。その結果,平使い及び縦使い方向の曲げ強度,引張強度及び圧縮強度については,推定値が実験値を上回り積層効果が示唆された。そこで,2・3plyの強度分布について,1plyの実験値の分布を用いてシミュレーションし,最尤法の推定による母集団分布と比較したところ,母集団分布の方が上に位置した。従って,1plyの縦使い方向の曲げ強度,引張強度及び圧縮強度には,積層効果が存在することが分かった。一方,平使い方向の曲げ強度には,存在するかどうか分からなかった。

In this study, we estimated the element strength distribution of Laminated Veneer Lumber (LVL) by the nonlinear least-squares method, supposing an element of veneer with adhesive. However, in order to validate this method, we must compare the element strength distribution estimated by this method with that calculated from experimental data. Then, we extracted specimens of 1ply, 2ply and 3ply with an adhesion layer from the remainders of LVL and carried out the same static tests as the experiments for LVL. Comparing the experimental values of 1ply and the estimated values in the previous report, the latter were larger than the former for Modulus of rapture (MOR) in the horizontal and vertical use directions, and tension and compression strengths. Accordingly, a laminating effect was suggested by those strengths. To ascertain this, the strength distributions of 2ply and 3ply were simulated by the experimental data of 1ply. Also the population distributions for the strengths of 2ply and 3ply were estimated by the maximum likelihood method. Comparing the strength distributions simulated by 1ply with the population distributions, the population distribution was larger for MOR in the vertical use direction, tension strength and compression strength. Therefore, in those strengths, it turned out that the laminating effect existed. On the other hand, we could not determine whether or not the laminating effect existed for MOR in the horizontal use direction.

Journal

  • Mokuzai Gakkaishi

    Mokuzai Gakkaishi 61(2), 55-66, 2015

    The Japan Wood Research Society

Codes

  • NII Article ID (NAID)
    130005060960
  • NII NACSIS-CAT ID (NCID)
    AN00240329
  • Text Lang
    JPN
  • ISSN
    0021-4795
  • NDL Article ID
    026286571
  • NDL Call No.
    Z17-484
  • Data Source
    NDL  J-STAGE 
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