quantifying ductility in timber structures

en 1995 complies with the principles of en 1990, but it is only concerned with requirements for mechanical resistance, serviceability, durability and fire resistance. when it comes to the principle stating that potential damage shall not be disproportionate to the original cause, and the principle statement on limitations of potential damage, en 1995 offers very little help on how to fulfil these principles. in ultimate limit states there are no recommendations or guidance on deformations, rotations or other measures for evaluation of, to what extent, a timber structure fulfils the basic principles of en 1990.

ductility and robustness of timber structures are high on the agenda of the cost action e55. contributions are needed in order to develop methods for verification of compliance with the basic principles of en 1990. the most common opinion in recent literature is that this can be achieved by utilization of plastic deformation of metallic fasteners. however, although numerous experimental results on the behavior of timber structures, timber connections and metallic fasteners are reported, no unified methods exist for evaluation of these results in this context. in en 1995, the required properties are not stated, nor is there any method available for verification. in the paper some procedures are proposed and discussed. furthermore, some ductility measures are used in evaluations of examples from tested structural timber connections. the results are discussed in view of the definition of ductility and the basic requirements of design put forward in en 1990.