Using Tsai-Wu Material Model (Orthotropic Plastic)

Using the Timber Design add-on, timber column design is possible according to the 2018 NDS standard ASD method. Accurately calculating timber member compressive capacity and adjustment factors is important for safety considerations and design. The following article will verify the maximum critical buckling strength calculated by the Timber Design add-on using step-by-step analytical equations as per the NDS 2018 standard including the compressive adjustment factors, adjusted compressive design value, and final design ratio.

In this article, the adequacy of a 2x4 dimension lumber subject to combined biaxial bending and axial compression is verified using the RF-/TIMBER AWC add-on module. The beam-column properties and loading are based on example E1.8 of AWC Structural Wood Design Examples 2015/2018.

In RFEM 5 as well as RSTAB 8 in RF-/FOUNDATION Pro, you can save the foundation dimensions for all five foundation types as foundation templates in a user-defined database and use them later in other models.

In RFEM, the oriented strand board (OSB) material is available for the USA and Canada. The material parameters are taken from the "Panel Design Specification manual".

Using the "Beam Panel" thickness type, you can model timber panel elements in 3D space. Simply specify the surface geometry and the timber panel elements are automatically generated using an internal member-surface construct, including the element connection stiffness. The Beam Panel thickness type is defined using the Multilayer Surfaces add-on.

A "beam panel" provides you with the following advantages:

• Single-sided or double-sided sheathing
• Automatic calculation of a semi-rigid coupling between studs and sheathing
  • Nailed sheathing connection
  • Stapled sheathing connection
  • User-defined sheathing connection
• Representation as a complete geometric 3D object (frame, studs, surface, etc.), including eccentricity and automatically calculated stiffness between elements
• Consider openings via surface cells
• Design of the individual structural elements utilizing the Timber Design add-on (full shear wall design planned for a future release)
• Other material options available (e.g., particle board, gypsum, or fiberboard sheathing with cold-formed steel sections)

• Go to Explanatory Video

You have the option to perform the fire resistance design of surfaces using the reduced cross-section method. The reduction is applied over the surface thickness. It is possible to perform the design checks for all timber materials allowed for the design.

For cross-laminated timber, depending on the type of adhesive, you can select whether it is possible for individual carbonized layer parts to fall off, and whether you can expect increased charring in certain layer areas.

• Go to Explanatory Video