Weld line assessment - 2 horizontal welds V0001.xls Download

Description:

The method of assessing fillet welds groups treating welds as lines is reasonably safe and conservative and is very convenient to use.

 

a) Weld subject to bending....See table below for typical unit areas and unit Moments of Inertia

 

1) The area of the fillet weld A_u..(unit thickness) is calculated assuming the weld is one unit thick..

2) The (unit) Moment of Inertia I_u is calculated assuming the weld is one unit thick..

3) The maximum shear stress due to bending is determined...τ_b = M.y/I_u

4) The maximum shear stress due to direct shear is determined.. τ_s = P /A

5) The resultant stress τ_r = Sqrt (τ_b² + τ_s² )

6) By comparing the design stress S_s with the resultant stress τ_r the value of the weld throat thickness is calculated and then the weld size.i.e. if the τ_r /S_s = 5 then the throat thickess t = 5 units and the weld leg size h = 1,414t

a) Weld subject to torsion...See table below for typical unit areas and unit Polar moments of Inertia

A fillet weld subject to torsion is easily assessed as follows.

1) The area of the fillet weld A_u (unit thickness) is calculated assuming the weld is one unit thick

2) The (unit) Polar Moment of Inertia J_u is calculated assuming the weld is one unit thick.. The polar moment of inertia J = I_xx + I_yy

3) The maximum shear stress due to torsion is determined...τ_t = T.r/J_u

4) The maximum shear stress due to direct shear is determined.. τ_s = P /A _u

 

5) The resultant stress τ_r is the vector sum of τ_t and τ_s. r is chosen to give the highest value of τ_r

 

6)By comparing the design stress S_s with the resultant stress τ_r the value of the weld throat thickness is calculated and then the weld size.i.e. if the τ_r /S_s = 5 then the throat thickess t = 5 units and the weld leg size h = 1,414t

Calculation Reference
Schaum's Outline - Machine Design
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Submitted On:

29 Jan 2008

Submitted By:

John Doyle (JohnDoyle)

File Date:

24 Jan 2007

File Size:

58.50Kb

File Type:

xls

Downloads:

225

Rating:

Total Votes:2

Comments:

Harry Burt 2007-06-19 10:28:10 Looks like Blodgett's approach, which I have always found effective. I would like to see a metric/inch choice. (Unless I missed it. If so, I rate this a 5)