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Message #08246
[Branch ~yade-dev/yade/trunk] Rev 3002: - add capability to deactivate the damping in NewtonIntegrator for individual particle via O.bodi...
------------------------------------------------------------
revno: 3002
committer: Klaus Thoeni <klaus.thoeni@xxxxxxxxx>
branch nick: yade
timestamp: Tue 2012-01-24 14:29:29 +1100
message:
- add capability to deactivate the damping in NewtonIntegrator for individual particle via O.bodies[id].state.isDamped=False
- use this new property in examples/WireMatPM/wirecontacttest.py
modified:
core/State.hpp
examples/WireMatPM/wirecontacttest.py
pkg/dem/NewtonIntegrator.cpp
--
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=== modified file 'core/State.hpp'
--- core/State.hpp 2011-02-14 08:05:09 +0000
+++ core/State.hpp 2012-01-24 03:29:29 +0000
@@ -59,7 +59,8 @@
((Vector3r,inertia,Vector3r::Zero(),,"Inertia of associated body, in local coordinate system."))
((Vector3r,refPos,Vector3r::Zero(),,"Reference position"))
((Quaternionr,refOri,Quaternionr::Identity(),,"Reference orientation"))
- ((unsigned,blockedDOFs,,,"[Will be overridden]")),
+ ((unsigned,blockedDOFs,,,"[Will be overridden]"))
+ ((bool,isDamped,true,,"Damping in :yref:`Newtonintegrator` can be deactivated for individual particles by setting this variable to FALSE. E.g. damping is inappropriate for particles in free flight under gravity but it might still be applicable to other particles in the same simulation.")),
/* additional initializers */
((pos,se3.position))
((ori,se3.orientation)),
=== modified file 'examples/WireMatPM/wirecontacttest.py'
--- examples/WireMatPM/wirecontacttest.py 2011-10-06 03:29:16 +0000
+++ examples/WireMatPM/wirecontacttest.py 2012-01-24 03:29:29 +0000
@@ -117,6 +117,7 @@
#### import block as a sphere after net has been created
bloc=O.bodies.append(sphere([1.0,1.0,0.65],radius=0.15,wire=False,highlight=False,color=[1,1,0],material=blocMat))
+O.bodies[bloc].state.isDamped=False # switch damping off since free fall under gravity
#### plot some results
=== modified file 'pkg/dem/NewtonIntegrator.cpp'
--- pkg/dem/NewtonIntegrator.cpp 2012-01-23 14:43:54 +0000
+++ pkg/dem/NewtonIntegrator.cpp 2012-01-24 03:29:29 +0000
@@ -39,7 +39,7 @@
void NewtonIntegrator::updateEnergy(const shared_ptr<Body>& b, const State* state, const Vector3r& fluctVel, const Vector3r& f, const Vector3r& m){
assert(b->isStandalone() || b->isClump());
// always positive dissipation, by-component: |F_i|*|v_i|*damping*dt (|T_i|*|ω_i|*damping*dt for rotations)
- if(damping!=0.){
+ if(damping!=0. && state->isDamped){
scene->energy->add(fluctVel.cwise().abs().dot(f.cwise().abs())*damping*scene->dt,"nonviscDamp",nonviscDampIx,/*non-incremental*/false);
// when the aspherical integrator is used, torque is damped instead of ang acceleration; this code is only approximate
scene->energy->add(state->angVel.cwise().abs().dot(m.cwise().abs())*damping*scene->dt,"nonviscDamp",nonviscDampIx,false);
@@ -157,7 +157,7 @@
if (state->blockedDOFs!=State::DOF_ALL) {
// linear acceleration
Vector3r linAccel=computeAccel(f,state->mass,state->blockedDOFs);
- cundallDamp2nd(dt,f,fluctVel,linAccel);
+ if(state->isDamped) cundallDamp2nd(dt,f,fluctVel,linAccel);
//This is the convective term, appearing in the time derivation of Cundall/Thornton expression (dx/dt=velGrad*pos -> d²x/dt²=dvelGrad/dt*pos+velGrad*vel), negligible in many cases but not for high speed large deformations (gaz or turbulent flow).
linAccel+=prevVelGrad*state->vel;
//finally update velocity
@@ -165,11 +165,11 @@
// angular acceleration
if(!useAspherical){ // uses angular velocity
Vector3r angAccel=computeAngAccel(m,state->inertia,state->blockedDOFs);
- cundallDamp2nd(dt,m,state->angVel,angAccel);
+ if(state->isDamped) cundallDamp2nd(dt,m,state->angVel,angAccel);
state->angVel+=dt*angAccel;
} else { // uses torque
for(int i=0; i<3; i++) if(state->blockedDOFs & State::axisDOF(i,true)) m[i]=0; // block DOFs here
- cundallDamp1st(m,state->angVel);
+ if(state->isDamped) cundallDamp1st(m,state->angVel);
}
}
