Reliability-based design (RBD) procedures for engineered structures are being developed and quickly gaining acceptance by cade agencies throughout the world. Numerous organizations are involved in the development of national or regional cades without the benefit of interchange of ideas and methodologies. Harmonization and coordination of these activities is absolutely essential if the ever-increasing international commerce is to flourish. This NATO Advanced Research Workshop (ARW) was organized to bring together, for the first time, experts on RBD and related subjects from various countries to assess the current knowledge and recommend new developments. Further, due to their unique nature and great economic significance in most parts of the world, special emphasis was placed on engineered wood structures. For example, in North America more wood products are used in construction than ali other materials (steel, concrete, brick, etc.) combined. However, the wood industry segment, historically, receives less attention and smaller financial support for new developments than other construction materials. RBD developments are being conducted in Similar, but largely independent, Europe, North America, New Zealand and Australia. Experts from these regions were brought together to exchange information on current work, propose new developments and to provide means of international coordination. Thus, this ARW provided an opportunity to advance the cause of RBD of engineered wood structures.

A model was developed for predicting the statistical distribution of glued-laminated beam strength and stiffness under normal temperature conditions using available long span modulus of elasticity data, end joint tension test data, and tensile strength data for laminating-grade lumber. The beam strength model predictions compared favorably with test data for glued-laminated beam strength data with 8 and 10 laminations; however, the model predicted strength values 30 percent higher for glued-laminated beam strength data with 4 laminations. Fire endurance and structural resistance were evaluated by artificially reducing the cross section. This reduction accounts for char depth as well as for reduced wood strength caused by the elevated temperature. Average time-to-failure predictions using the developed model compared well with those from conventional prediction methods.

Durability design methods used in Australia are generally uncoordinated and do not meet the changing needs of durability engineers. Durability design principles, environmental agents and the existing methods are summarised. An alternative method is proposed to allow engineers to reliably estimate the effect of environmental agents on the strengh and stiffness of timber members and joints. A Durability Coordinators Group is recommended to facilitate further debate.