Hi Javad, as we talked about in your hotline case, there are a couple of possible approaches for this. In either case you should first perform a static analysis.
Then, if you have access to the Adams Vibration plugin (Tools > Plugin Manager), perform a vibration analysis (Simulate > Vibration Analysis). Select the Normal Mode Analysis option.
Alternatively, if you do not have access to the Adams Vibration plugin, the .acf that was generated from the initial simulation can be edited to add: "linear/eigen". This can be run by using the ACF Runner (Review > Analysis Management > Run (acf)... ). Next, the results of the Eigen simulation must be read using Review > Analysis Management > Read.
Now, this post-processor can be used to view the results of the analysis: Right-clicking in the main window > Load Mode Shape Animation and then select the Table of Eigenvalues button in the lower portion of the window.
One trick that usually works is to export the model at a simulated position, read the adm into a blank A/view session and then perform the modal analysis.
Thank you all. I guess the problem with A/View is A/View may not correctly read the air springs, springs and other properties from the A/Car model.
I was able to run a suspension static load case followed by a linear/Eigen using A/Vibration to get my undamped natural frequencies. But, I noticed in the modal animation that the wheel initial positions are based on the wheel travel I requested. That may not be true!
The term "I guess" tells me that you didn't try lately.
I recommended reading the adm. There's mostly no such things like UDE's or property files. They're broken down to pure A/View elements like joints, and forces.
In past ADAMS versions they required the usersubs to be prsent in the solver. Nowadys everything should contain a ROUTINE statement which will find everything required. Well always assumed you have an A/Car installation and license.
BTW: You know that you can trigger LIN/EIGEN after a minimaneuver in the Event-Builder, do you ?
