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Subject: Re: [STRUC] Bonded contacts
Author: =?utf-8?Q?Odd_Einar_Lind=C3=B8e?=
Date: 2008-05-05 20:09:54

Just out of courosity... Are you comparing a standard (frictional) contact
with a bonded(glued)
contact ? (or did i miss something along the way).

Perhaps the de-bonding feature of a bonded contact element could help you?

Brgds O.E.Lindoe,ImencoAS

----- Original Message -----
From: "Christiane Caouette"
To: "ANSYS User Discussion List"
Sent: Monday, May 05, 2008 10:00 PM
Subject: Re: [Xansys] [STRUC] Bonded contacts


> Hello 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.
>
> I found only a couple of papers dealing with osseointegrated implants:
> the most interesting is a series of paper by Moreo and Doblaré. They use
> what they call an "interface element", but I think they programmed it
> themselves, it has little to do with Ansys inter20X elements. It's based
> on the same principles, but they use the damage variable d as a bonding
> degree, with their own behavior law (I can only use bilinear or
> exponential models in Ansys).
>
> 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!
>
> Thanks everyone!
> Christiane Caouette
> PhD Student at École de Technologie Supérieure
>
>> 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
>>
>>
>>
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Posts possibly associated with message #93156AuthorDateScore
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93133Re: [STRUC] Bonded contactsChristiane Caouette 2008/05/03 
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93163Re: [STRUC] Bonded contactsJoe Metrisin2008/05/06 
93164Re: [STRUC] Bonded contactsJoe Metrisin2008/05/06 
93167Re: [STRUC] Bonded contactsSalil Chirkute2008/05/06 
93190Re: [STRUC] Bonded contactsChristiane Caouette 2008/05/06 
93193Re: [STRUC] Bonded contactsOdd Einar Lindøe2008/05/06 
93198Re: [STRUC] Bonded contactsJim_YJ_Lin_at_wistron.com2008/05/07 
93199Re: [STRUC] Bonded contactsSalil Chirkute2008/05/07 
93214Re: [STRUC] Bonded contactsChristiane Caouette 2008/05/07