Sliding

[JOYE]

Dear Prof,
I have to solve a problem in which there are two blocks, the bottom one is fixed and the upper one is sliding, normal force is been applied in the bottom block which creates some Hertzian contact pressure between them. The frequency of the sliding block is around 1Hrtz and the total time is 100sec.
I am using the 8.3 FEAP version and nothing is documented for sliding in that.
Please suggest how to solve this problem.
Thank you.

[Prof. R.L. Taylor]

I believe this is sometimes referred to as an "ironing" problem.  There may be information in the contact literature on how the problem is solved.  However, you should note that in general we have not implemented any dynamic contact behavior in feap, so you may have to implement one -- like "rattle" or "shake" to be able to analyze your problem.

[JOYE]

Thank you Prof .for your reply, I understand what you mentioned and I will solve as you mentioned.
But could you please suggest to me about frequency (1 Hertz) of 'to' and 'fro' movement for a block in 100 secs, how to implement this?
It would be great if you explain with an example.

Thank You.

[Prof. S. Govindjee]

The dynamic part of the loading should be set up using the PROP command in FEAP; this will allow you to set up a sinusoidal loading function with a given frequency and amplitude.

So something like

batch
  prop,,1
end
1 1  0  tm  0  0 am fq 0

where tm is the max time of your loading protocol, am is the amplitude and fq is the frequency.  See the user manual for further details.