If you want compression only springs you need to use an iterative process. And solve many consecutive matrixes.
You could set the springs as new members with a non-linear material with a normal young modulus in compression and a very small one for tension to avoid convergence problems.
You need a software which support at least non-linear materials then you could define an elastic modulus in compression and other with a small slope (non zero for convergence issues)in tension. Them, use this non-linear material for the track.
"Traditional" analysis is not completely rigid, because you have an inflection point at neutral axis. If you add strain compatibility, then the analysis is rigid. Check RAM Connection software and this link as alternative to FEM...
Take a look to RAM Connection software and this paper for more accurate design including biaxial analysis
http://communities.bentley.com/products/structural/structural_analysis___design/b/analysis_and_design_blog/archive/2010/09/08/biaxial-analysis-of-general-shaped-base-plates.aspx
Well, do not concern by this warning, you just change the number of modes to calculate to 1.
The eignen values are directly related to the vibration modes, then you have only one degree of freedom (mass in one direction for example) therefore RAM Advanse only could found one eigne value in MASS...
Hi,
P-delta is an iterative non-linear analysis then in some load cases probably do not converge, you can change the parameters in the analysis form,like increse iteration number or iteration steps or decrese the tolerance the parameters by default are:
Number of steps= 1
Number of Iteration=...
