Single Friction Pendulum Bearing Element problem

[Mohammadzadeh]

Hello
In the below file If the scale is equal to 4.0 , The analysis will not done.why?

http://opensees.berkeley.edu/wiki/index ... PS2d_3.tcl


Best regards

[aschellenberg]

The maximum scale factor that will still work for this example is ~1.7.

The reason is that at a scale factor of 1.7 you already get a horizontal displacement of 15.7 in. Given that the radius of the sliding surface for this example is 34.68 in. you are already nearly on the vertical portion of the sliding surface (to illustrate this I suggest you draw a circle with radius of 34.68 in. and then see where you are on the circle at a horizontal displacement of 15.7 in.).

The other issue is that the vertical motion is getting scaled by the same factor and you start having a lot of uplift. At a scale factor of 1.7 you will get nearly 2 in. of uplift. The impact following this uplift will cause numerical convergence issues. I recommend assigning a vertical material with some small amount of viscous damping to help with convergence. I updated the example files on the Wiki to illustrate how to do this. So please look at the updated examples.

[Mohammadzadeh]

Dear Andreas
Thank you so much.

[Muradilomame]

Hello Andreas,

How can we calculate the value of the stiffness of the vertical material and the damping ratio because changing them dramatically changes the results?

Thanks in advance of your reply and illustration,
Murad Ilomame
PhD student at University of Waterllo