Crippling In web And Flange

[designz]

i have a situation of beam. the beam is crippled. but the problem is top flange and the bottom flange of the beam are bent in opposite directions. i am trying to figure what made the faliure in the beam. i never saw such type of failure. d oanyone know anything about it or aware of such failure in the beam. any information on this will be very helpful.
my intial thought was lateral loads might have caused it but due to the top flange and bottom flange bents i am not sure if my assumption is right.
can anyone help.

 

[tolchijb]

Is this a built up plate girder? If it is, it sounds like the flange to web weld unzipped causing both flanges to become unstiffened and buckle independently.

 

[rb1957]

if it has truly crippled, the flanges have a 50% chance that they'll deflect in the same direction, and a 50% chance that they'll deflect in opposite directions.

if it is a C-channel it could be transverse loads causing bending about the weak axis.

 

[designz]

thanks for your response.
it is a built up section and the crippiling is only on the flanges and not on the web and is about 1/3 distance of the whole length of beam.
there is no welding issue also.

 

[tolchijb]

A picture or a sketch would help.

 

[designz]

don not know if this picture helps any

 

[hokie66]

Looks like impact to me. See the notch on the bottom flange? Impact in weak axis of beam also caused top flange to buckle.

 

[ToadJones]

I agree with Hokie 100%.
I actually had a chance to see this same thing happen to a small highway bridge girder (over pass). I piece of construction equipment hit the bottom flange and bent it up very similar to what you have, and the top also buckled slightly, but not directly from the impact....more of a secondary effect.
I think Hokie is right.