Question

Consider the following statements related to lug angle:

If the main member is an angle,

1. the strength of lug angles and fastener connecting lug angle to gusset plate should be at least 20% more than the force in outstanding leg.

2. the strength of the fastener connecting lug angle and main member should be at least 40% more than the force in outstanding leg.

3. the whole area of the member is net area less deduction for bolt holes.

Which of the above statements are correct?

2 and 3 only

1 and 3 only

1 and 2 only

1, 2 and 3

Answer ( Option C)

1 and 2 only

Solution

Lug angle is an additional angle used along with tension member to reduce the length of conection.

• The effective connection of the Lug angles shall be as far as possible terminate at the end of the member connected.

• The connection of Lug angle to main member shall preferably start in advance of the member to the gusset plate.

• Minimum of two bolts, rivets or equivalent welds be used for attaching Lug angles to the gusset.

• If the main member is angle:

(a) The whole area of the member shall be taken as the effective rather than net effective section (i.e. with reduction for outstanding Leg area). The whole area of the member is the gross area less deduction for bolt holes.

(b) The strength of Lug angles and fastener connecting Lug angle to gusset plate should be atleast 20% more than the force in outstanding Leg.

(c) The strength of the fastener connecting Lug angle and main member shall be atleast 40% more than the force carried by the outstanding leg.

• In case the main member is a channel and like:

(a) As far as possible Lug angles should be placed symmetrically.

(b) The strength of fasteners connecting Lug angle to the gusset should be atleast 10% more than the force not accounted for by the direct connection of the member and the attachment of the Lug angles to the member shall be capable of developing 20% in excess of that force.