Short-time procedure for fatigue assessment of beech wood and adhesively bonded beech wood joints
Timber as a structural material has experienced a revival for aspects related to sustainability, positive effect on interior building and increased architectural possibilities. To overcome a series of limitations related to partly obsolete traditional techniques, timber engineering sets high expectations on adhesive bonding as a joining method. Research on adhesively bonded timber joints has proven their superiority over mechanical fasteners in terms of strength and stiffness. Research on methods to design adhesively bonded timber joints under static loads is currently ongoing and significant progress has already been achieved. The topic of fatigue behaviour, however, has only been addressed very rarely, largely because “classical” methods for fatigue assessment based on Woehler curves, is extremely time-consuming. This paper aims to fill this gap by describing and validating an advanced time- and cost-efficient approach to quantify the behaviour of bonded timber joints under fatigue. Therefore the fatigue behaviour of beech wood as base material and adhesively bonded beech wood joints as structural elements were investigated by means of a short-time procedure. In this approach, cyclic tests with a stepwise increase of the stress amplitude were performed while the plastic strain amplitude was measured. The plastic strain amplitude gives reliable signals for an estimation of the fatigue strength. This is validated by traditional cyclic tests with constant stress amplitudes. It could be shown that the testing approach provides reliable results and has a high potential in time and cost savings for wood and adhesively bonded wood joints.
KeywordsFatigue Wood Adhesive Measurement techniques Short-time testing method
- 1.Bodig J, Jayne BA (1982) Mechanics of wood and wood composites. New York, Van Nostrand Reinhold, ISBN 0442008228Google Scholar
- 5.Estévez J, Otero D, Martín E, Vázquez JA (2010) The use of adhesive bulbs in the inner end of drills in order to improve the axial strength of steel threaded bars glued in timber. In: World conference of timber engineering (WCTE), Riva del Garda. 20–24 June 2010Google Scholar
- 6.ISO 12107 (2003), Metallic materials: fatigue testing: statistical planning and analysis of data. International Organization for Standardization, GenevaGoogle Scholar