Statics problems with higher orders of indeterminacy 2

[JohnnyB423]

Hi all,

Could anyone point me in the direction of the easiest way to solve statics problems that have 5 or more degrees of indeterminacy?
I can post the specific structure I am trying to solve if that would help.
Any tips or examples would be greatly appreciated.

Thanks,

Jon

 

[Tomfh]

If it’s statically indeterminate you can’t solve it by statics. You need stiffness compatibility analysis, eg matrix analysis/finite element analysis. Most general purpose structural analysis programs will do this for you.

 

[Retrograde]

http://repository.bakrie.ac.id/10/1/[TSI-LIB-131][Aslam_Kassimali]_Matrix_Analysis_of_Structure.pdf

 

[ClearCalcs]

If you’re looking to solve them by hand, look into the moment distribution method. My understanding is that it was the “best” way to analyze indeterminate structures before the arrival of computers. Tricky at first but once you get it, it’s quite procedural and easy to apply.

Others like the force method can get pretty unwieldy at that level of indeterminacy.

-Laurent

 

[IDS]

The link post by retrograde is a good resource, but it's a bit long.

For multi-span continuous beams there are various methods that are quite simple to set up on a spreadsheet.

For anything more complex a frame analysis using the stiffness method is probably the best option.

See: Frame Analysis with Excel for links to a series of posts on how to set up a frame analysis in Excel, from simple examples to fully functioning programs.



Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[JohnnyB423]

Thanks for the responses everyone! I will have to take a look at these resources.

 

[rb1957]

assuming it isn't a continuous beam, or other, which has it's own rather simple/direct solutions, FEA would be my typical approach. 5 redundancies is getting too much of a handfull for matrix methods.

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

 

[IDS]

assuming it isn't a continuous beam, or other, which has it's own rather simple/direct solutions, FEA would be my typical approach. 5 redundancies is getting too much of a handfull for matrix methods.

Eh?

FEA is a matrix method.

But why go for FEA rather than a frame analysis for analysing a frame structure?

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/