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No rating yet Subject: Re: [STRUC] Bonded contacts Author: Christiane Caouette Date: 2008-05-05 20:00:34Hello everyone,
Joseph: Yes, I did read section 14.174. It is very complete in almost every aspect of contact technology in Ansys (I must add release 11 is greatly improved compared to 10!). The only missing info in there is about contact surface behavior (bonded, standard, rough...): they only say that "contact points are attached" for bonded contact, whatever that means...
Martin: You're absolutely right; I did all that testing during my master's... :-) . To simulate primary stability (the implant's just been put in, no cellular reaction yet), standard contacts did a fine job as long as FKN and FKT where properly set. But if I use bonded contacts (with penalty algorithm and same FKN/FKT), micromotions (contact sliding distance) drop to almost nothing. That is the behavior I need to explain mathematically.
Paris: I had no idea LSDyna could do that sort of stuff, I will look into it, because damage control/induced is exactly what I need. As for papers on this subject, most of them focus on primary stability and try to reproduce lab experiments with composite femurs; there's no osseointegration, it's simple classic contact mechanics, so they do it with contact elements, most of the time not saying what values they used as parameters. You'll find those all over the place (just type something like "hip stem model"...), but primary stability is the easy part.
So, to summarize: Paris seems to have the key to my problem, I'll go look in LS-Dyna, and give the list an update when I know more... probably a couple weeks from now!
> Hi Christiane, > If ANSYS is not an option due to limitations of its contact algorithms you may want to try LsDyna that has different contact types that account for separation under controlled situations. The LSDyna may be an overkill but the types of contact algorithms it offers are more appropriate for your type of problem. You want erosion-type or damaged-induced/controlled contact resolutions that I know LsDyna can help. It appears that your problem is not centered in the contact interface per se but more so in its the existence or absense and the effect it has to the parts at the interface. > > Having said all that, I know that pretty soon I'll run into a paper/work by someone in your field for the very similar problem that was done in ANSYS. > > Incidentally, what is the literature search showing as far as handling problems like yours ?? What other codes engineers in your field use for similar problems ??? > > Regards, > Paris Altidis > Belcan Corp. > 630-786-0008 > > > ^-------------------------------------------------------- | XANSYS - www.xansys.org | | The Discussion List for users of ANSYS, Inc. Software | | Hosted by PADT - www.padtinc.com | ^--------------------------------------------------------