Wood Column Bending & Deflection

[Anonymous]

Is there a way to use Robot For Structural Analysis to place a 20' 4x4 wood column of Douglas Fir species and load it with (perhaps node or point load?) and then perform an analysis to see how much bending and or buckling is occurring just in that one column? I had tried to set one up in building project mode by placing the wood column and adding supports at both ends however when it came time to perform calculations in automatic mode that I was alerted by a message box that there were nodes that had some type of difficulty (type 2 was listed...)

I would like to run calculations manually to start out with an example point load much like is talked about in basic examples of Newtonian Mechanics.

Thank You!

[EduardoMeruvia]

hi @Anonymous , 

You should be able to model what you are after in Robot, can't see a reason why it wouldn't work. 

Could you upload your robot model? might be easier to help that way. 

[Anonymous]

Screenshots are attached of steps taken

I understand that the pinned connection used at the top of the column might not be what is needed. I was hoping for an explanation if the top needs to be pinned of some sort to analyze....

The formulas for wood column bending are described in American Wood Council NDS for solid columns (fc)

[EduardoMeruvia · Accepted solution]

If you are analysing as a simply supported column, either as an sway or non-sway frame type, then you shouldn't be putting a pinned support at the top. You would only need a lateral restrain at the top i.e. Support with UX and UY fixed only so the column can take axial forces. Putting a lateral restrain a the top, would make your structure statically determined, and would run in Robot without any errors/warnings.