Blog List

Friday, 21 October 2016

Rolling shear modulus and strength of beech wood laminations

Simon Aicher1 / Zachary Christian1 / Maren Hirsch1
1Materials Testing Institute, University of Stuttgart, Timber Constructions, Pfaffenwaldring 4b, 70569 Stuttgart, Germany
Corresponding author: Simon Aicher, Materials Testing Institute, University of Stuttgart, Timber Constructions, Pfaffenwaldring 4b, 70569 Stuttgart, Germany
©2016 Simon Aicher et al., published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. (CC BY-NC-ND 3.0)
Citation Information: Holzforschung. Volume 70, Issue 8, Pages 773–781, ISSN (Online) 1437-434X, ISSN (Print) 0018-3830, DOI: 10.1515/hf-2015-0229February 2016

Publication History

Published Online:


Previous research indicated that the rolling shear properties of European beech wood (Fagus sylvatica) are considerably higher than those of softwood. The aim of the presented investigation was to substantiate previous data on rolling shear modulus and strength of European beech wood and to further evaluate its substitution of softwoods in applications where shear properties are influential, namely as cross layers in cross-laminated timber (CLT). Further, the effect of the annual ring orientation within the boards on shear modulus and strength was of major interest. The beech specimens comprised four different sawing patterns, classified unambiguously with reference to the pith location. The shear properties were determined by 50, two-plate shear tests with specimen cross-section dimensions of 33 mm × 135 mm. A mean rolling shear modulus of 370 N mm-2 was obtained, whereby no significant detrimental effect for pith boards with cracks was observed. In agreement with continuum mechanics, the semi-quarter-sawn boards revealed the highest shear moduli whereas the quarter-sawn boards showed roughly 30% lower values. The mean rolling shear strength was 5.6 N mm-2 for all specimens, whereby pith specimens resulted in generally lower values. The 5% quantile, disregarding pith specimens, was 4.5 N mm-2. In conclusion, the rolling shear strength and modulus exceed the respective characteristic values for softwoods by roughly factors of 5 and 7, indicating great potential for beech wood cross-layers in CLT.
Keywords: cross-laminated timber (CLT)densityEuropean beechoff-axis propertiesrolling shear modulusrolling shear strengthsawing patterntwo-plate shear test


Rolling shear modulus and strength of the cross layers are decisive mechanical properties in cross-laminated timber (CLT) plates. The composite material CLT is built up in the slab thickness direction by orthogonally crossed layers of boards, hereby closely resembling solid wood-wise the classical plywood build-up of thin, cross-wise layered veneers. Currently, CLT, which is of ever increasing importance globally for medium and high-rise timber buildings, is almost exclusively manufactured from softwood (spruce/fir) boards. All existing European CLT approvals, which are based on the former European Common Understanding Procedure (OIB 2005) or the present European Assessment Document (EOTA 2015) as well as the recently approved European CLT standard EN 16351 (2015) address exclusively softwoods as lamination material. In recent years, the use of hardwoods in wooden construction products has become an ever increasingly important topic in central Europe. Lower grade beech wood (Fagus sylvatica, Linnaeus 1753) is utilized almost entirely thermally, but it is obvious that this material should be very apt for CLT buildups. This hypothesis is based on the assumption that the rolling shear properties of beech are probably very satisfactory (Stamer and Sieglerschmidt 1933Hoefflin and Aicher 2000Niemz et al. 2015). The intention is to gain a deeper insight into the mechanical properties of beech wood for homogeneous and hybrid CLTs within the framework of an ongoing European WoodWisdom research project on hardwoods. The present paper reports on the rolling shear modulus and strength investigations of single beech board slabs with emphasis on the boards’ sawing patterns and herewith associated growth and drying defects.

Theoretical background, materials, and methods

Results and discussion




  • Aicher, S., Dill-Langer, G. (2000) Basic considerations to rolling shear modulus in wooden boards. Otto-Graf-J. 11:157–165.
  • ASTM standard (2006) D2718 Standard test methods for structural panels in planar shear (rolling shear). ASTM International, West Conshohocken, PA.
  • DIBt European approval (2013) ETA-10/0241 Leno Cross Laminated Timber – Solid wood slab elements to be used as structural elements in buildings.
  • DIBt Technical approval (2014) Z-9.1-705. 2K-EP adhesive WEVO-Spezialharz EP 32 S with WEVO hardener B22 TS for glued-in steel rods in timber building products.
  • Dumail, J.-F., Olofsson, K., Salmén, L. (2000) An analysis of rolling shear of spruce wood by the Iosipescu method. Holzforschung 54:420–426.
  • EN standard (2004) 789 Timber structures – Test methods – Determination of mechanical properties of wood based panels. European Committee for Standardisation, Brussels, Belgium.
  • EN standard (2006) 14358 Timber structures – Calculation of characteristic 5-percentile values and acceptance criteria for a sample. European Committee for Standardisation, Brussels, Belgium.
  • EN standard (2012) 408 Timber structures – Structural timber and glued laminated timber – Determination of some physical and mechanical properties. European Committee for Standardisation, Brussels, Belgium.
  • EN standard (2015) 16351 Timber structures – Cross laminated timber – Requirements. European Committee for Standardisation, Brussels, Belgium.
  • EOTA European Assessment Document (2015) EAD 130005-00-0304. Solid wood slab element to be used as a structural element in buildings.
  • Feldborg, T. (1991) Determination of some mechanical properties of timber in structural sizes. Proc. Int. Timber Eng. Conf., 2:2189–2199, London.
  • Fellmoser, P., Blaß, H.J. (2004) Influence of rolling shear modulus on strength and stiffness of structural bonded timber elements. Paper CIB-W18/37-6-5, Proc. Meeting 37, Karlsruhe.
  • Hoefflin, L., Aicher, S. (2000) Wave velocities in the radial-tangential growth plane of spruce and beech. In: Proc. Int. Conf. on Wood and Fiber Composites, University of Stuttgart: 327–337.
  • Jakobs, A. (2005) Zur Berechnung von Brettlagenholz mit starrem und nachgiebigem Verbund unter plattenartiger Belastung mit besonderer Berücksichtigung des Rollschubs und der Drillweichheit. PhD Thesis, Universität der Bundeswehr, Munich.
  • Kollmann, F. Technologie des Holzes und der Holzwerkstoffe. Springer, Berlin, 1982.
  • Mestek, P. (2011) Punktgestützte Flächentragwerke aus Brettsperrholz (BSP) – Schubbemessung unter Berücksichtigung von Schubverstärkungen. PhD thesis. Technische Universität München.
  • Niemz, P., Ozyhar, T., Hering, S., Sonderegger, W. (2015) Zur Orthotropie der physikalisch-mechanischen Eigenschaften von Rotbuchenholz. Bautechnik, 92:3–8.
  • OIB European Technical Assessment (2014) ETA-14/0349. Massive plattenförmige Holzbauelemente für tragende Bauteile in Bauwerken.
  • OIB Common Understanding of Assessment Procedure (CUAP) Solid wood slab element to be used as a structural element in buildings. ETA request no. 03.04/06, Vienna.
  • Stamer, J., Sieglerschmidt, H. (1933) Elastische Formänderung der Hölzer. Ver. Dtsch. Ing. 77:503–505.
  • Tsai, S.W., Hahn, H.T. Introduction to composite materials (Vol. 1). CRC Press, Lancaster, 1980.
  • Zhou, Q.Y., Gong, M., Chui, Y.H., Mohammad, M. (2014) Measurement of rolling shear modulus and strength of downscaled cross laminated timber using bending and two-plate shear tests. Wood Fiber Sci. 46:259–269.

For further details log on website :

No comments:

Post a Comment

Mangrove Forest Management & Restoration

The Sabah Forestry Department has conserved most if not all Mangrove Forests under Class V for marine life conservation and as a natural me...