The main objective of the Action was to extend established statistical methods and structural mechanics models by taking into account the specific properties of wood, wood based materials and joints, allowing an optimised analyse of the reliability of timber structures and structural systems and thus contributing to a technical and economical optimisation of complex timber structures as well as consequently strengthening the competitiveness of the forest industries sector. Building on its comprehensive state of the art review of the scientific research on probabilistic modelling of timber material, joints and systems, the Action has been able to create a harmonised set of data on material and joint properties by compiling detailed information provided by the signatory countries. One of the key scientific achievements, and the main outcome of the Action, is the development of a multi-level methodology for the reliability analysis of timber structures. In close cooperation with the Joint Committee of Structural Safety (JCSS) the Probabilistic Model Code, a mathematical tool for the analysis of reliabilities has been written following the existing models for steel and concrete. This methodology taking into account the specific properties of the used raw materials (species, type of grading, information on grading parameters, etc.) is consistent with the concept used for the elaboration of Eurocode 5. The Final Conference held at the beginning of September 2005 in Arcachon offered a platform to discuss the broad variety of statistical methods and models for graded timber and joints allowing the investigation of the influence of grading on the distributional characteristics of timber. All those procedures have been integrated in the Probabilistic Model Code elaborated by this Action. Furthermore, probabilistic models for the analysis of timber in bending, taking into consideration the aspects related to moisture and the duration of load effects, have been presented. A huge number of accompanying documents can be found at the highly informative Action Web-site (http://www.km.fgg.uni-lj.si/coste24/coste24.htm) containing also the three main documents: the state of the art report on ‘reliability analysis of timber structures’, the Probabilistic Model Code (PMC) and the proceedings of the Final Conference.
