yade-dev team mailing list archive

[Chareyre <666246@xxxxxxxxxxxxxxxxxx>]

Hi Sergei,

Are you sure these lines apply for facet-sphere?

> +	const Vector3r c1x = geom.radius1*geom.normal;
> +	const Vector3r c2x = -geom.radius2*geom.normal;
>    

For the facet, couldn't it be something like :

const Vector3r c2x = (geom.contactPoint - de2.pos + shift2) ?


This is what would happen if the shear increment/velocity used in the 
constitutive law were defined using ScGeom::getShear()/getIncidentVel(), 
and if values were precomputed with avoidRatcheting=false.

I see that, currently in Ig2_Facet_Sphere, avoidRatcheting is true (my 
bad), I recommend turning it false :
Ig2_Facet_Sphere_ScGeom.cpp:110 : 
scm->precompute(state1,state2,scene,c,normal,isNew,shift2,*_true_*);

Bruno

-- 
periodic boundary don't work with ViscEl classes
https://bugs.launchpad.net/bugs/666246
You received this bug notification because you are a member of Yade
developers, which is subscribed to Yade.

Status in Yet Another Dynamic Engine: Fix Committed

Bug description:
Periodic boundary don't work with Ig2_Facet_Sphere_ScGeom and Ig2_Sphere_Sphere_ScGeom functors.


#=============BEGIN SCRIPT TEST PERIODIC WITH Ig2_Sphere_Sphere_ScGeom==========
# -*- coding: utf-8

from yade import utils

sphereRadius=0.1
tc=0.001# collision time 
en=0.3  # normal restitution coefficient
es=0.3  # tangential restitution coefficient
density=2700
frictionAngle=radians(35)# 
params=utils.getViscoelasticFromSpheresInteraction(tc,en,es)
sphereMat=O.materials.append(ViscElMat(density=density,frictionAngle=frictionAngle,**params))


# Spheres
sphId=O.bodies.append([
	utils.sphere( (i*0.2+0.1,0.5,0.2), 0.1, material=sphereMat) for i in range(5)
	])
O.bodies[sphId[-1]].state.vel=(0.5,0.5,0)

## Engines 
O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
	InteractionLoop(
		[Ig2_Sphere_Sphere_ScGeom()],
		[Ip2_ViscElMat_ViscElMat_ViscElPhys()],
		[Law2_ScGeom_ViscElPhys_Basic()],
	),
	NewtonIntegrator(damping=0),
]

O.periodic=True
O.cell.refSize=Vector3(1,1,1)

O.dt=.01*tc

O.saveTmp()
#==========================END======================


#=============BEGIN SCRIPT TEST PERIODIC WITH Ig2_Facet_Sphere_ScGeom==========
# -*- coding: utf-8

from yade import utils

sphereRadius=0.1
tc=0.001# collision time 
en=0.3  # normal restitution coefficient
es=0.3  # tangential restitution coefficient
density=2700
frictionAngle=radians(35)# 
params=utils.getViscoelasticFromSpheresInteraction(tc,en,es)
facetMat=O.materials.append(ViscElMat(frictionAngle=frictionAngle,**params)) 
sphereMat=O.materials.append(ViscElMat(density=density,frictionAngle=frictionAngle,**params))

floor
n=5.
s=1./n
for i in range(0,n):
	for j in range(0,n):
		O.bodies.append([
			utils.facet( [(i*s,j*s,0.1),(i*s,(j+1)*s,0.1),((i+1)*s,(j+1)*s,0.1)],material=facetMat),
			utils.facet( [(i*s,j*s,0.1),((i+1)*s,j*s,0.1),((i+1)*s,(j+1)*s,0.1)],material=facetMat),
		])

# Spheres
sphId=O.bodies.append([
	utils.sphere( (0.5,0.5,0.2), 0.1, material=sphereMat),
	])
O.bodies[sphId[-1]].state.vel=(0.5,0,0)

## Engines 
O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb()]),
	InteractionLoop(
		[Ig2_Facet_Sphere_ScGeom()],
		[Ip2_ViscElMat_ViscElMat_ViscElPhys()],
		[Law2_ScGeom_ViscElPhys_Basic()],
	),
	GravityEngine(gravity=[0,0,-9.81]),
	NewtonIntegrator(damping=0),
]

O.periodic=True
O.cell.refSize=Vector3(1,1,1)

O.dt=.01*tc

O.saveTmp()
#==========================END======================