Thank you all. I appreciate it. Kan
On Fri, Jun 6, 2008 at 4:01 AM, <[EMAIL PROTECTED]> wrote: > Send Yade-users mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.berlios.de/mailman/listinfo/yade-users > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Yade-users digest..." > > > Today's Topics: > > 1. Re: How is the cohesion treated in YADE? (Bruno Chareyre) > 2. Re: How is the cohesion treated in YADE? (V?clav ?milauer) > 3. Re: How is the cohesion treated in YADE? (kan) > 4. How to reset a body's velocity? (sega) > 5. Re: How to reset a body's velocity? (Lionel Favier) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 05 Jun 2008 12:14:03 +0200 > From: Bruno Chareyre <[EMAIL PROTECTED]> > Subject: Re: [Yade-users] How is the cohesion treated in YADE? > To: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=UTF-8; format=flowed > > CohesiveFrictionalContactLaw is indeed the law you need, Kan. > Janek added bending/twisting moments to this contact law recently. > Moments are only elastic for now, but implementing plasticity for > moments would be just few lines as you have all kinematic variables > defined already (like the relative bending/twisting rotations between > bodies). > 2 Remarks : > -you need to set collider->haveDistantPersistent=true if you want > interactions with tensile forces (overlap<0) > -you will have to set interaction->isReal=true in the contact law if you > want the collider to delete lost interactions (loss of contact means > adhesive properties are lost and overlap<0, this is equivalent to > contactForce=0). > > Bruno > > > > > > Jerome Duriez a ?crit : > > > >> > >> is the cohesion property of some kind of material (like rock) treated > >> in YADE? > >> if so, how it is modeled? bonded model? > >> > > Hello. It depends on the contact law you use... > > For example you could have cohesion in > > CohesiveFrictionalContactLaw (see the files in > > pkg/dem/Engine/StandAloneEngine/). For each interaction a value of > > cohesion "c" named in fact "shearAdhesion" is computed depending on a > > caracteristic "shearCohesion" (member of the class > > "CohesiveFrictionalRelationships) and on the radii of the bodies in > > contact. > > This value of cohesion will then be used for computing a maximum value > > of tangential contact force : Ftmax = c + Fn * tan(phi). > > > > Jerome > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Yade-users mailing list > > [email protected] > > https://lists.berlios.de/mailman/listinfo/yade-users > > > > > -- > > _______________ > Chareyre Bruno > Maitre de conference > > Institut National Polytechnique de Grenoble > Laboratoire 3S (Soils Solids Structures) - bureau E145 > BP 53 - 38041, Grenoble cedex 9 - France > T?l : 33 4 56 52 86 21 > Fax : 33 4 76 82 70 43 > ________________ > > > > ------------------------------ > > Message: 2 > Date: Thu, 05 Jun 2008 14:15:29 +0200 > From: V?clav ?milauer <[EMAIL PROTECTED]> > Subject: Re: [Yade-users] How is the cohesion treated in YADE? > To: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=UTF-8 > > There is the brefcom model (in extra) that is supposed to do just that > (cohesion) and is formulated using continuum mechanics (strain/stress) > rather than particles and there is code to make the transition from > displacements/positions etc to normal strain, shear strain and back from > stresses to forces. The material model itself cannot be disclosed, but > you can easily add your own. It is pretty much work in progress now, > however. > > For cohesion, make sure you use enable distant contacts in > PersistentSAPCollider and > InteractingSphere2InteractingSphere4SpheresContactGeometry. The old > approach would use persistentContacts, but there are (by general > consensus) deprecated and will be removed. > > Vaclav > > Hi, > > > > is the cohesion property of some kind of material (like rock) treated > > in YADE? > > if so, how it is modeled? bonded model? > > > > Thanks. > > Kan > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Yade-users mailing list > > [email protected] > > https://lists.berlios.de/mailman/listinfo/yade-users > > > > > > ------------------------------ > > Message: 3 > Date: Thu, 5 Jun 2008 09:26:57 -0500 > From: kan <[EMAIL PROTECTED]> > Subject: Re: [Yade-users] How is the cohesion treated in YADE? > To: [email protected] > Message-ID: > <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="utf-8" > > Hi, Dear Jerome, > > Thank you for your instruction. > In my contact model, I use the bonded-particle model, so I just assume the > cohension force is modeled in the bond. In that case, the parameter of > cohension c is not explicit shown in the model. maybe it is the problem of > my code. > I will read the code and study how it is modeled in YADE. > > Thanks a lot. > kan > > > On 6/5/08, [EMAIL PROTECTED] < > [EMAIL PROTECTED]> wrote: > > > > Send Yade-users mailing list submissions to > > [email protected] > > > > To subscribe or unsubscribe via the World Wide Web, visit > > https://lists.berlios.de/mailman/listinfo/yade-users > > or, via email, send a message with subject or body 'help' to > > [EMAIL PROTECTED] > > > > You can reach the person managing the list at > > [EMAIL PROTECTED] > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of Yade-users digest..." > > > > > > Today's Topics: > > > > 1. How is the cohesion treated in YADE? (kan) > > 2. Re: How is the cohesion treated in YADE? (Jerome Duriez) > > > > > > ---------------------------------------------------------------------- > > > > Message: 1 > > Date: Wed, 4 Jun 2008 14:56:28 -0500 > > From: kan <[EMAIL PROTECTED]> > > Subject: [Yade-users] How is the cohesion treated in YADE? > > To: [email protected] > > Message-ID: > > <[EMAIL PROTECTED]> > > Content-Type: text/plain; charset="utf-8" > > > > Hi, > > > > is the cohesion property of some kind of material (like rock) treated in > > YADE? > > if so, how it is modeled? bonded model? > > > > Thanks. > > Kan > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: > > > https://lists.berlios.de/pipermail/yade-users/attachments/20080604/2009b6ab/attachment-0001.html > > > > ------------------------------ > > > > Message: 2 > > Date: Thu, 05 Jun 2008 10:21:44 +0200 > > From: Jerome Duriez <[EMAIL PROTECTED]> > > Subject: Re: [Yade-users] How is the cohesion treated in YADE? > > To: [email protected] > > Message-ID: <[EMAIL PROTECTED]> > > Content-Type: text/plain; charset="utf-8" > > > > > > > > > > is the cohesion property of some kind of material (like rock) treated > > > in YADE? > > > if so, how it is modeled? bonded model? > > > > > Hello. It depends on the contact law you use... > > For example you could have cohesion in CohesiveFrictionalContactLaw > > (see the files in pkg/dem/Engine/StandAloneEngine/). For each > > interaction a value of cohesion "c" named in fact "shearAdhesion" is > > computed depending on a caracteristic "shearCohesion" (member of the > > class "CohesiveFrictionalRelationships) and on the radii of the bodies > > in contact. > > This value of cohesion will then be used for computing a maximum value > > of tangential contact force : Ftmax = c + Fn * tan(phi). > > > > Jerome > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: > > > https://lists.berlios.de/pipermail/yade-users/attachments/20080605/2829f7c9/attachment-0001.html > > > > ------------------------------ > > > > _______________________________________________ > > Yade-users mailing list > > [email protected] > > https://lists.berlios.de/mailman/listinfo/yade-users > > > > > > End of Yade-users Digest, Vol 24, Issue 3 > > ***************************************** > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > https://lists.berlios.de/pipermail/yade-users/attachments/20080605/aa86a611/attachment-0001.html > > ------------------------------ > > Message: 4 > Date: Fri, 6 Jun 2008 12:31:35 +0400 > From: sega <[EMAIL PROTECTED]> > Subject: [Yade-users] How to reset a body's velocity? > To: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="iso-8859-1" > > Hi! > I need to reset a body's velocity to zero when this body is reloaded into a > simulation. > Now can I do it? > As me seems, a velocity of body is sets _only_ by > LeapFrogPositionIntegrator or NewtonsDampedLaw. > Both have a firsts vector but different parents... > > -- > Best regards, Sergei D. > > > ------------------------------ > > Message: 5 > Date: Fri, 06 Jun 2008 13:15:26 +0200 > From: Lionel Favier <[EMAIL PROTECTED]> > Subject: Re: [Yade-users] How to reset a body's velocity? > To: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > sega a ?crit : > > Hi! > > I need to reset a body's velocity to zero when this body is reloaded into > a simulation. > > Now can I do it? > > As me seems, a velocity of body is sets _only_ by > LeapFrogPositionIntegrator or NewtonsDampedLaw. > > Both have a firsts vector but different parents... > > > > > Hi Sega, > > If you need to do that during the simulation with a body which has a > current velocity, acceleration .. Maybe you could add these lines in > "LeapFrogPositionIntegrator" (additions in italics) > > Real dt = Omega::instance().getTimeStep(); > > /ParticleParameters * p = YADE_CAST<ParticleParameters*>(b.get());/ > > / if (p->vel_nulle) > { > p->acceleration = Vector3r(0,0,0); > prevVelocities[id] = Vector3r(0,0,0): > }/ > > if (!firsts[id]) > p->velocity = prevVelocities[id]+((Real)0.5)*dt*p->acceleration; > > You have also to declare the parameter /vel_nulle/ as a boolean in > "ParticleParameter" > > finally you can initialise your velocity by adding a line, for example > in "VelocityRecorder.cpp" (additions in italics) > > for( ; bi!=biEnd ; ++bi ) > { > shared_ptr<Body> body = *bi; > if( body->isDynamic ) > { > size+=1.0; > ParticleParameters* pp = > YADE_CAST<ParticleParameters*>(body->physicalParameters.get()); > > /pp->vel_nulle = true;/ > > x+=pp->velocity[0]; > y+=pp->velocity[1]; > z+=pp->velocity[2]; > } > } > > Normally it works, I just don't know if that is really fits YADE > philosophy, maybe the YADE's big boss could comment. > > good luck > > Lionel > > // > > -- > Lionel FAVIER > Doctorant > Laboratoire Sols Solides Structures, Risques (3S-R) > Equipe Risques et Vuln?rabilit? (RV) > > Domaine Universitaire - BP 53 > 38041 Grenoble Cedex 9 > France > > T?l: +33 (0)4 56 52 86 36 > [EMAIL PROTECTED] > > > > ------------------------------ > > _______________________________________________ > Yade-users mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/yade-users > > > End of Yade-users Digest, Vol 24, Issue 4 > ***************************************** >
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