Re: Yade-users Digest, Vol 5, Issue 7

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> Today's Topics:
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>    1. Re: Rotation without friction in discrete model ? (Bruno Chareyre)
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 07 Nov 2006 15:40:13 +0100
> From: Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>
> Subject: Re: [Yade-users] Rotation without friction in discrete model
> 	?
> Message-ID: <45509ACD.1030908@xxxxxxxxxxx>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Problem is I've no big time for this at the moment.
> Lionel : can you look into a saved xml and see if the shear component of
> contact forces are 0?
> Then, come in my office, i'll have 5min :).
>
> Bruno
>
>
> Janek Kozicki a ?crit :
>
>
>> Lionel Favier said:     (by the date of Tue, 07 Nov 2006 11:46:55 +0100)
>>
>>
>>
>>
>>> Hi,
>>>
>>> I'm currently using the Elastic Contact Law for my discrete model of a
>>> flow down an inclined plane, and I noticed a surprising thing.
>>> When I use 0 as a value for the friction angle, I observe that the
>>> angular velocity of one element after contact with another element is
>>> not equal to 0 (The initial angular velocity is equal to 0).
>>> So the obtained value of the angular velocity is negligible, but it's
>>> not equal to zero whereas it should be because there is no shear force
>>> in that case.
>>> Do you know where is this coming from ?
>>>
>>>
>>>
>> Bruno, can you look at that? I'll be able to check it on friday, not quicker.
>>
>> Lioner, please just check if the boxes have zero friction angle too
>> (not only spheres).
>>
>>
>>
>>
>
>
>
Hi,

That is not a problem with the boxes.
To check it, I have simulated two elements in tangential contact with
zero for the both friction angles. A saved xml file during contact give
me a value of ' ... 10^-9' for the angular velocity, so that is
negligible in fact, whereas the shear force is at zero on the same xml file.

Lionel
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