With timber or wood-based structures, deformation rather than strength behaviour will commonly be the limiting factor in design and as such, a lack of understanding of design requirements may lead to under or over-designed timber members and connections. BS EN 1995-1-1:2004 is the Eurocode dealing with the design rules for buildings supported by timber structures, but the requirements for deriving structural deformations at different limit states are not always clearly presented or indeed defined. This paper aims to give guidance to the users of the Eurocode on the determination of instantaneous and creep deformations at the serviceability limit states and proposes a method for deriving deformations at the ultimate limit states, should this be required.
Jack Porteous, BSc, MSc(Eng), DIC, PhD, CEng, MIStructE, FICE
Director, Jack Porteous Consultancy, Scotland
Abdy Kermani, BSc, MSc, PhD, CEng, MIStructE, FIWSc
Professor of Timber Engineering, Edinburgh Napier University, Scotland