FEAP User Forum

FEAP => Programming => Topic started by: nima_ikm on October 21, 2015, 06:20:30 AM

Title: Initializing of displacement for Newton–Raphson loop
Post by: nima_ikm on October 21, 2015, 06:20:30 AM

Dear Feap Users,

I would like to initialize my Newton–Raphson, i.e. Eq. 18.3  FEAP user manual only for first step. However, I found the command ' INITial DISPlacements '. I am not sure this is right command or not and also I would like to know, how I can impose initial displacement for all D.o.F. Is it possible to use the following command:

BATCh
INITial DISPlacements
END
     Include name of file

Thank you for your time and kind help.

Best regards

Title: Re: Initializing of displacement for Newton–Raphson loop
Post by: Prof. R.L. Taylor on October 21, 2015, 12:06:26 PM

This is what Sect 14 of manual says too!  Should work fine

Title: Re: Initializing of displacement for Newton–Raphson loop
Post by: nima_ikm on October 25, 2015, 02:19:42 PM

Dear Prof. Taylor,

I am so appreciated and grateful for your kind help and answer. Thank you very much.

Also, I have another question. In  the newton raphson loop for the first time step, initial tangent stiffness is assigned with linear elastic. However, in my case, I need to initialized my tangent stiffness matrix. This initial sparse tangent stiffness matrix is given in one text file. I would be appreciated, if you could let me know that if it is possible to initialize stiffness matrix for the first time increment.

Kind regards

Title: Re: Initializing of displacement for Newton–Raphson loop
Post by: Prof. R.L. Taylor on October 26, 2015, 08:46:49 AM

You will need to modify the program to add what you want to do.  It is something very specific and not an option we can do for you.