WireMat -> Change Force Displacement curve during simulation

Hi everyone,

I've got an issue in my simulation. I want to change the properties of a WirePhys interaction during the simulation. I thought about two options to do this :
- Deleting the existing interaction and changing the existing Wiremat for a new one with the wanted properties. But in this case, the new interaction (added with "createInteraction(id1,id2)") is not taken into account in the simulation (the interaction exist during 1 step and then disappear). Maybe you have a idea why ? But let's concentrate on the second option.
- The second option I tried is directly change the properties in the WirePhys by modifying "O.interactions[id1,id2].phys.displForceValues". But in this case, the new properties are not taken. You can see it in this little script below.

Have you any idea how to solve this ? I put my script of the second option below,
Thank you,
Loïc

##############################################################################

# encoding: utf-8

from yade import qt, plot
from yade.gridpfacet import *
import gts, os, locale, sys
import numpy as np

O.engines=[
 ForceResetter(),
 InsertionSortCollider([Bo1_Sphere_Aabb()]),
 InteractionLoop(
                 [Ig2_Sphere_Sphere_ScGeom()],
                 [Ip2_WireMat_WireMat_WirePhys()],
                 [Law2_ScGeom_WirePhys_WirePM()]),
 NewtonIntegrator(gravity=(0,0,0),damping=0.1,label='newton'),
 PyRunner(initRun=False,iterPeriod=1500, nDo = 2,command='modif()'),
 PyRunner(initRun=True,iterPeriod=1000,command='addPlotData()'),]

RWire = 0.012
SSvalues = [(5.16,1.54e8),(130,1.67e8),(103280,3.9e12)]
Wiremat = O.materials.append(WireMat(young=1e9, poisson=0.3,frictionAngle=radians(10),density=1000,isDoubleTwist=False,diameter=2*RWire,strainStressValues=SSvalues))

Wire = []
Wire.extend([
O.bodies.append(utils.sphere([0,-RWire,0],RWire,wire=False,fixed=False,material=Wiremat)),
O.bodies.append(utils.sphere([0,+RWire,0],RWire,wire=False,fixed=False,material=Wiremat))])

O.bodies[Wire[1]].state.blockedDOFs='xyzXYZ'
O.bodies[Wire[0]].state.vel[1]=-0.05
O.bodies[Wire[0]].state.blockedDOFs='xyzXYZ'

plot.plots={'U':('F')}
plot.plot(noShow=False, subPlots=False)
v=qt.Controller()
v=qt.View()
rr = qt.Renderer()
rr.intrAllWire = True

O.dt = 1e-5
O.saveTmp()
O.run()

def addPlotData():
    F = O.forces.f(Wire[0])[1]
    U = O.bodies[Wire[0]].state.pos[1] - O.bodies[Wire[0]].state.refPos[1]
    plot.addData(U=-U*1000, F=F/1000 )

def modif():

    O.pause()
    NewFD = [
    (-0.179,-100000),
    (-3.12,-105000),
    (-2500,-1.4e9),]
    print NewFD[0]
    print NewFD[1]
    print NewFD[2]

    O.interactions[Wire[0],Wire[1]].phys.displForceValues[1] = NewFD[0]
    O.interactions[Wire[0],Wire[1]].phys.displForceValues[2] = NewFD[1]
    O.interactions[Wire[0],Wire[1]].phys.displForceValues[3] = NewFD[2]

    print O.interactions[Wire[0],Wire[1]].phys.displForceValues[1]
    print O.interactions[Wire[0],Wire[1]].phys.displForceValues[2]
    print O.interactions[Wire[0],Wire[1]].phys.displForceValues[3]