The shear strength and failure modes of timber joists obtained from the torsion test method.

Khokhar, Aamir Muhammad; Zhang, Hexin; Ridley-Ellis, Daniel

Abstract

This paper presents details of the experimental method and test results from a series of torsion tests undertaken to evaluate the shear strength of timber joists. The failure modes and the correlation of shear strength and torsional shear modulus were also studied. Test results obtained indicate that shear strength of tested joists was higher than the published values in EN 338 and in the USDA Wood Handbook. The test joists fractured mostly at the middle with cracks propagated towards either supports or edges. However, combined tension shear and crushing failure modes were sometimes observed at supports. A good correlation was found between torsional shear strength and the shear modulus, but, it appeared that knots do not have substantial influence on the shear strength. The recent revision of the testing standard EN408 includes the torsion testing approach to obtain the shear modulus of timber. It is proposed that a torsion test also be adopted as a method for evaluating the shear strength of timber

Citation

Khokhar, A. M., Zhang, H., & Ridley-Ellis, D. (2010, June). The shear strength and failure modes of timber joists obtained from the torsion test method. Presented at 11th World Conference on Timber Engineering 2010, Riva del Garda, Italy

• Conference Name: 11th World Conference on Timber Engineering 2010
• Start Date: Jun 20, 2010
• End Date: Jun 24, 2010
• Publication Date: 2010
• Deposit Date: May 27, 2015
• Publicly Available Date: May 27, 2015
• Publisher: Trees and Timber Institute, National Research Council
• Peer Reviewed: Peer Reviewed
• Pages: 3509-3516
• Book Title: 11th World Conference on Timber Engineering 2010 (WTCTE 2010)
• Chapter Number: Session 63 Failure Analysis 1 : Volume 4
• ISBN: 9781622761753
• Keywords: Torsion test; Shear strength; Shear modulus; Design values; Failure mechanism
• Public URL: http://researchrepository.napier.ac.uk/id/eprint/8236