what does HACK mean?

[Alan]

Dear professor,

I find a puzzling comment on line 124 of geoqtq.f and I don't quite understand the meaning of HACK. In addition, why the program must be returned (nothing will be run) when the csw=14. Could you give me some advice? Thanks in advance.

Best.

[Prof. R.L. Taylor]

The three dimensional contact was mainly developed by another user.  When it was integrated into feap the initial set of history variables was probably never fully debugged so the return under csw.eq.14 was added with a proviso that at some later date it would be revisited - which obviously it never was.

The set is not needed for most problems in which the gap is positive, it may cause problems if the meshing produces some initial penetraiton and needs adjustment.

Development of new contact based on mortar (surface-surface) instead of node-surface is needed still.

[Alan]

Dear professor,
 
Thank you very much for your help! But I have another question: according to your answer, the codes of cnts3d.f when the csw =14 are incomplete, is it the reason that the 3D explicit contact cannot be executed correctly? I have made two tests, one is a 2D explicit contact test and it can be run successfully, because the program of cnts2d.f is complete including csw=14, the other is a 3D explicit contact test and it always reports errors, of course you have told me that feap cannot do the explicit contact, but cnts3d.f has the program when csw=6(an indicate of explicit solution), is there something that I have misunderstand?

Could you please give me more details? Because I have read the program in cnts3d.f(csw=6) carefully, but I cannot find a bug. According to my feeling, the 3D explicit contact should be run successfully, however, in fact, it can't.

Thanks for your help in advance.

Best.

[Prof. R.L. Taylor]

Can you post the 2-d and 3-d input files you are trying to do the contact so I can see what may be missing from the csw=14 step.

[Alan]

Dear professor,

Of course.