Skip to main content
Journal of Wood Science

Official Journal of the Japan Wood Research Society

Download PDF
  • Original Article
  • Published:

Effect of laminate configuration on the modulus of elasticity of glulam evaluated using a strain gauge method

Journal of Wood Science volume 53, pages 31–39 (2007)Cite this article

Abstract

The purpose of this study was to measure the strain of glulam laminae by affixing a strain gauge at the central axis of the lateral face in order to determine the effect of the configuration of the glulam. Japanese cedar and southern pine were used in the study. The strain and stress of the laminae during the bending test were recorded, and the modulus of elasticity (MOE) was calculated. The influence of the MOE of the adhesive layers was also considered. Results showed that the MOE of the laminated elements increased as its specific gravity increased, although the specific gravity was not the only factor evaluated. The MOE of glulam (E bsg) measured by the strain gauge method was very close to the observed MOE of glulam (E b) and a significant linear relationship was identified. The MOE (e) of laminae measured by the strain gauge method was very close to that determined (E) under the “free condition” before bonding. The difference between the modified MOE (E bsa) and E bsg was not significant. The MOE of glulams made of heterogeneously graded lumbers were about 23% and 31% larger than the average MOE of their laminae for Japanese cedar and southern pine, respectively. The actual neutral axis was just below the longitudinal center line. It shifted slightly within the proportional limit range and moved downward when the load increased.

References

  1. Peterson J, Madson G, Moody RC (1981) Tensile strength of one-, two-, and three-ply glulam members of 2 by 6 Douglas-fir. Forest Prod J 31:42–48

    Google Scholar 

  2. Ross RJ, Pellerin RF (1994) Nondestructive testing for assessingwood members in structure: a review. FPL-GTR-70. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  3. Erikson RG, Gorman TM, Green DW, Graham D (2000) Mechanicalgrading of lumber sawn from small-diameter lodgepolepine, ponderosa pine, and grand fir trees from northern Idaho. Forest Prod J 50:59–65

    Google Scholar 

  4. Burdzik WMG, Nkwera PD (2002) Transverse vibration tests forprediction of stiffness and strength properties of full size Eucalyptusgrandis. Forest Prod J 52:63–67

    Google Scholar 

  5. Wang X, Ross RJ, Mattson JA, Erickson JR, Forsman JW, Geskse EA, Wehr MA (2002) Nondestructive evaluation techniques for assessing modulus of elasticity and stiffness of small-diameter logs. Forest Prod J 52:79–85

    Google Scholar 

  6. Wang SY, Lin SH (1996) Effect of plantation spacing with qualityof visually graded lumber and mechanical properties of Taiwangrown Japanese cedar. Mokuzai Gakkaishi 42:435–444

    Google Scholar 

  7. Wang SY, Ko CY (1998) Dynamic modulus of elasticity and bendingproperties of large beams of Taiwan-grown Japanese cedarfrom different plantation spacing sites. Mokuzai Gakkaishi 44:62–68

    Google Scholar 

  8. Hernandez R, Moody RC (1992) Improved performance of southernpine structural glued-laminated timber. Research Paper FPLRP-514. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  9. Manbeck HB, Janowiak JJ, Blankenhorn PR, Labosky P, Moody RC, Hernandez R (1993) Red maple glulam timber beam performance. Research Paper FPL-RP-519. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  10. Janowiak JJ, Manbeck HB, Hernandez R, Moody RC, Blankenhorn PR, Labosky P (1995) Efficient utilization of redmaple lumber in glued-laminated timber beams. Research Paper FPL-RP-541. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  11. Moody RC, Hernandez R, Davalos JF, Sonti SS (1993) Yellowpoplar glulam timber beam performance. Research Paper FPLRP-520. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  12. Falk RH (1997) Design and performance aspects of United States and European glulam. Proceedings of the Conference on Research Standardization Applications, Institute for Steel Construction, Wood Construction, and Industrial Construction, Technical University Graz, Austria, 6 June 1997, pp C/2-1-C/2-21

  13. Falk RH, Colling F (1995) Laminating effect in glued-laminated timber beams. J Struct Eng ASCE 121:1857–1863

    Article  Google Scholar 

  14. Lee JJ, Park JS, Kim KM, Oh JK (2005) Prediction of bending properties for structural glulam using optimized distributions of knot characteristics and laminar MOE. J Wood Sci 51:640–647

    Article  Google Scholar 

  15. Yamada M, Takada M, Sano A (2001) Fire-resistance performance of structural LVL (4). Abstracts of the 51st Annual Meeting of the Japan Wood Research Society, p 425

  16. Wang SY, Cho JL (1985) Studies on the dynamic and acoustic behaviors of wood (III). Forest Prod Ind 4:2–26

    Google Scholar 

  17. Okuma M (1967) Studies on the mechanical properties of plywood. Bull Tokyo Univ Forest 63:1–60

    Google Scholar 

  18. Wang SY, Chang T (1978) Studies on the flexural properties of laminated beams with different wood species (1). Bending modulus of elasticity. Q J Chinese Forest 11:43–52

    Google Scholar 

  19. Markwart LJ, Wilson TRC (1935) Strength and related properties of woods grown in the United States. USDA Technical Bulletin 479, Washington DC

  20. Doyle DV, Markwart LJ (1966) Properties of southern pine in relation to strength grading of dimension lumber. Research Paper FPL-64. USDA Forest Service, Forest Products Laboratory, Madison, WI

    Google Scholar 

  21. Bodig J, Jayne BA (1982) Mechanics of wood and wood composites. Van Nostrand Reinhold, New York

    Google Scholar 

  22. Ohlsson S, Perstorper M (1992) Elastic wood properties from dynamic tests and computer modeling. J Struct Eng ASCE 18:2677–2690

    Article  Google Scholar 

  23. Isoda H, Mori T, Sasagawa A (2000) The resistance and fracture mechanisms of glulam beams in bending. J Struct Construct Eng 529:13–20

    Article  Google Scholar 

  24. Kollmann F, Cote WA (1968) Principles of wood science and technology, vol 1. Solid wood. Springer, Berlin Heidelberg New York, pp 359–379

    Book  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. School of Forest Resource and Conservation, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, 106, Taiwan, ROC

    Te-Hsin Yang, Song-Yung Wang, Ming-Jer Tsai & Far-Ching Lin

  2. Taiwan Forest Research Institute, Taipei, Taiwan, ROC

    Cheng-Jung Lin

Authors
  1. Te-Hsin Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Song-Yung Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Cheng-Jung Lin
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Ming-Jer Tsai
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Far-Ching Lin
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Far-Ching Lin.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Yang, TH., Wang, SY., Lin, CJ. et al. Effect of laminate configuration on the modulus of elasticity of glulam evaluated using a strain gauge method. J Wood Sci 53, 31–39 (2007). https://doi.org/10.1007/s10086-006-0818-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10086-006-0818-z

Key words