📄 Axial with Moment
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Axial with Moment

The Axial with Moment design brief is the most common used in timber design as it incorporates compression, shear, moment and deflection checks all in the one brief. When the timber design is linked to either a MasterFrame model or a single or multi-span beam in MasterBeam, the briefs used are the axial with moment design check. In these two linked situations the forces and moments are automatically picked up from the model for each of the timber beam/column/rafter members in the model. Each member can then be designed or checked.

Alternatively, the timber design axial with moment check can be used independently, where the forces and moments are entered manually for each brief. The data to be entered includes the member length, along with the effective member lengths in both axes. Alternatively, the effective length can be controlled by using a Kx and Ky factor. In this case enter the full length of the member in both Lx and Ly as these will be multiplied by the Kx and Ky factors in the calcs. A slenderness limit is assumed and can be altered if required.

The second table consists of the axial compression force and major and minor axis moments and shears. The member deflection can also be added.

Bearing Checks

The third table relates to the bearing checks for each axis. The end shear values are entered, along with the distance to the start of the bearing from the end of the member, and the bearing length.

  • Distance to bearing = the distance from the very end of the timber member to the start of the support area.
  • Bearing length = the actual length of the bearing contact area along the member.

Example, if the joist end is flush with the face of the wall and the wall thickness is 100 mm:

  • Distance to bearing = 0 mm (because the bearing starts right at the end of the joist).
  • Bearing length = 100 mm (because that’s the length of the wall in contact with the joist).

Floor Vibration Check

The fourth table data relates to a floor vibration check, which is not currently active in the axial with moment design brief. Use the Timber Beam or Timber Joist briefs if you need to carry out a vibration check.

There is also an option on the Materials and Specifications tab to run this design check using a flitched beam - see the Flitch Beam design below.

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Note:-  the values you enter manually are unfactored forces and moments for BS design and factored forces and moments when using EC design

Timber Deflections Guidance

Also see the following technical note on 📄 Timber Deflections to Eurocode 5 or pdf version: timber deflections to EN 1995-1-1:2004 + A1-2008. 

This relates to the final deflection of a timber beam designed with loading cases according to EN 1990.