A plate 200 mm wide and 15mm thick is to be welded to another plate by means of double parallel...

 [Q.1]

A plate 200 mm wide and 15mm thick is to be welded to another plate by means of double parallel fillets.The plates are submerged to a static load of 80kN. Find the length of weld if the permissible shear stress in the weld does not Exceed 65MPa

Solution 

Given Data:

Width = 200mm;

Thickness = 10mm;

Static load (P)= 80kN = 80X10^3N;

Permissible Shear Stress( τ ) = 65MPa = 65 N/mm^2

Now ,Let 

L = Length of weld and 

S = Size of the weld (i.e plate thickness)

We know that maximum load wich the plates can carry for double parallel fillet weld (P) 

80X10^3 =1.414*S*L*τ

80X10^3 =1.414*15*L*65    

Therefore , L = 58.3 mm

Also ,Adding 12.5 mm for weld run 

L = (58.3 + 12.5)mm =70.8mm 

Thanks