Cantilever column with geometric non linearity

[ateestructural]

I have a cantilever column of length 1m.

I have applied a lateral load of 200 kN uniformly distributed over the length of the column

I have carried out a geometric non linear analysis and see that the (maximum deformed) statistics are as follows:

-314.40 mm(translation X)
0.00 (translation Y)
-49.62 mm (translation Z)
0.00000(rotation X)
-0.38930 (rotation Y)
0.00000 (rotation Z)

I get a very high axial force on the column of 1565.60 kN

Since the translation and rotation is high I am guessing my high value of axial force is because my load (lateral) of 200 kN is NOT a follower load i.e. it DOES NOT REMAIN perpendicular to the column throughout. Thus, the load has a contribution / component along the axial direction resulting in high axial forces.

Is that possible? Any thoughts?

 

[ateestructural]

The load is 200 x 50 = 10000 kN NOT just 200

 

[rb1957]

please don't multipost

another day in paradise, or is paradise one day closer ?

 

[IDS]

10000 x sin(0.39) is about 3800 kN, so that seems to the right order of magnitude, compared with your axial force.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Shu Jiang PEng SE]

The column slenderness effects the geometry no-linear result. What is your column cross section dimension?

 

[whitwas]

The manual for the software will tell you if it's a follower load or not. It might also be implied by how you defined it. If you defined it as being in the X direction, then it should not be a follower load because you told it to be in the X direction, not transverse to the beam.

Another way to tell is be looking at the reaction forces. Is the net reaction force 10 000 kN in the +X direction, balancing an applied non-follower 10 000 kN in the -X direction? If there's any reaction force in the Z direction, then it would be a follower load.