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Offset Beam Deflection

Offset Beam Deflection

Offset Beam Deflection

(OP)
Hello all,

I am trying to do solve by hand the system as shown in the attachment. Solving the problem in 2D is not an issue in any of the planes. My question is the validity of the superposition of the results. I am assuming I treat the orthogonal loads as point moments in each of the the appropriate planes? If I do that, the results do not seem reasonable.
This is of course in preparation for writing some code, for the system.

Thanks,
MechMon

RE: Offset Beam Deflection

Where are your support points in the diagram?

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Offset Beam Deflection

Point moments or point loads??

RE: Offset Beam Deflection

(OP)
The screen capture is a simplified FBD. The main support would be coming off the vertical riser(+Z), the load going toward the back (-X)is a reaction force to another cross member.

The loads in the (-Z) direction are just random point loads. Although the timing of the loads is different. The first load applied would be toward the end then the middle then toward the elbow. The loads are then stationary until a process completes then they are all removed at the same time.

The point of failure is the 90º bend. I am just trying to ascertain the contributions of the various loads. My main concern is that the racking is a major component since the fracture always begins on the outboard side of the 90º bend.

I know when designing a shaft to transmit torque we just sum the forces and moments in the orthogonal planes. So I guess this application isn't any different then. Except that I'm not transmitting torque, I'm just resisting it.

Thanks for letting me think out loud.

   

RE: Offset Beam Deflection

At any point in the structure the sum of your actions and reactions should equate to zero. This applies to forces and moments in the x,y, and Z directions.

This will give you simultaneous equations which can be simplified by locating the point of inspection in line with one of the forces thus eliminating any moment from it at that point.

RE: Offset Beam Deflection

It is a lousy FBD. I don't see any axis labelled;I don't see where the point loads are located and where the support(s) is(are) located.  It seems that few people now a day can actually do an accurate FBD by hand.

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