How is the applied shear force calculated in the Tedds Steel Masonry Support (BS 5950) calculation?

Question

How is the applied shear force calculated in the Tedds Steel Masonry Support (BS 5950) calculation?

Answer

The applied shear force used in the design of the steel masonry support is based on the self-weight of the torsion and support beam, the masonry and any additional dead loading.

In the output, this is given as one variable without notes so does not explain the method used for calculation.

This will be discussed in the following example.

Example

In the following calculation we will not add any additional load to the beam so we can look solely at
the hidden calculation.

In the input, we can see there is a total applied shear force of 35.7 kN.

 

We can then view the information for the calculation of the self-weight in the Geometry panel.

 

The self-weight of the masonry on the Torsion beam = 140 mm x 2000 mm x 20 kN/m³ = 5.6 kN/m
The self-weight of the masonry on the Support angle = 100 mm x 2000 mm x 20 kN/m³ = 4 kN/m

Self weight of Beams

Self-weight of torsion beam = A_mb x rho_mb = 0.45 kN/m
Self-weight of angle = A_sb x rho_sb = 0.15 kN/m

Total Load

Total UDL = 5.6 kN/m + 4 kN/m + 0.45 kN/m + 0.15 kN/m = 10.2 kN/m
Length = 5000 mm
Unfactored load = 10.5 kN/m x 5 m = 51 kN
Factored load = 51 kN x 1.4 = 71.4 kN
Shear this produces = 71.4 kN / 2 = 35.7 kN