Horizontal Stabilisation of Sheathed Timber Frame Structures Using Plastic Design Methods – Introducing a Handbook Part 3: Basics of the Plastic Design Method

AbstractDesign of shear walls has been a topic of major discussions to develop a common European code for design of timber structures. The main problem has been that shear walls are fastened to the substrate in different ways in different countries and that this fact must be reflected in the code. In this part the requirements are given that must be met for the ductile characteristics of the sheathing-to-framing joints in order for the plastic design method to be applicable. The method is based on the plastic lower bound theory. The fundamental prerequisites for the method are that the static equilibrium for the structure is fulfilled and that the sheathing-to-framing joints are ductile. What requirements that should be made on the mechanical properties of the joints for the plastic design methods to be applicable and the precaution measures to take to avoid brittle behaviour are discussed. The two main principles for anchoring of sheathed timber frame shear walls, fully and partially anchored, are illustrated showing the static behaviour of the walls and the force distribution in the framing members and the sheathings. In addition, a general description of the design in the serviceability limit state is given. For medium-rise and taller buildings the serviceability limit state needs to be taken into account. There are no specified criteria for deformations in the present code

Lengthwise bending strength variation of structural timber

In an experimental investigation the variation of the bending strength within and between structural timber members has been determined. (To model the variation of the bending strength a so-called hierarchical model with two levels has been formulated. This is the simplest type of probabilistic model to be used for describing equicorrelation between the bending strength values of the weak zones within the same timber member. The experiment data seem to be reasonably well represented by the formulated model.