Hello, you must specify your broadphase method. In case of collision between
two setof, the right broadphase is the 'raw' one.
<PlugIn Id="_ManageCollision" Between="body/body"
Set1="Fiber" Set2="Matrix" BroadPhase="Raw"
CallBack="Standard" Stiffness="1e7" RestitutionCoeff="0.5" />
DA.