Simplified modelling of timber-framed walls under lateral loads

• Mathematical modelling of timber-framed walls.
• A braced frame with one fictive diagonal is used.
• Model is suitable for analysis of lateral loads on the timber frame structure.
• Simplicity of the model, easy to use and suitability to use it with simpler and cheaper programs.

In the current paper a simple mathematical model with a fictive diagonal for a quick and accurate determination of the racking stiffness of composite timber-framed wall elements is developed. The stiffness of the timber-framed wall is determined through the analytical calculation of the wall element, taking into account the bending and the shear flexibility of the composite wall element, the flexibility of the fasteners between the timber frame and the sheathing board along with the flexibility of the tensile and compressive support at the foundations. The model furthermore allows for consideration of the walls with door and window openings in addition to that of tensile cracks appearing in the fibre–plaster sheathing boards, with the stiffness of the wall element being reduced. By varying the fictive diagonal cross-section of the numerical model according to the presented facts, the appropriate stiffness of the timber-framed wall can be obtained and used in the 3D static model. The model is suitable for any three-dimensional modelling with the analysis of the lateral load impact (wind, earthquake) on the building being carried out by using simple 3-dimensional FEM software, which is extremely useful for engineering application.