In Classical Mechanics the convention is compression negative and
tension positive. However, in Contact Mechanics (see Hertzian theory as
well as Johnsons et al.) the convention holds a positive sign for
compression and a negative one for tension (e.g. adhesion normal force
is negative whether presents). I would warmly suggest to follow the
latter convention, hence as positive the force applied by b1 on b2 if
normal is b1->b2.
--
NormalShearInteraction::{normalForce,shearForce} has undefined orientation
https://bugs.launchpad.net/bugs/493102
You received this bug notification because you are a member of Yade
developers, which is subscribed to Yade.
Status in Yet Another Dynamic Engine: Confirmed
Bug description:
NormalShearInteraction::{normalForce,shearForce} should contain forces on the
interaction, which can be used for various purposes by other functions.
However, different functors use them with different sign
ef2_Spheres_Elastic_ElasticLaw (a.k.a. ElasticContactLaw):
applyForceAtContactPoint(-currentContactPhysics->normalForce-shearForce, ...
)
Law2_Dem3DofGeom_CpmPhys_Cpm:
applyForceAtContactPoint(BC->normalForce+BC->shearForce, ...)
This is a convention issue, but must be fixed. Should normalForce and
shearForce be oriented as it applies on id1 (first case) or id2 (second case)?
2nd case is nicer WRT applyForceAtContactPoint syntax, but that one is
arbitrary as well.
_______________________________________________
Mailing list: https://launchpad.net/~yade-dev
Post to : [email protected]
Unsubscribe : https://launchpad.net/~yade-dev
More help : https://help.launchpad.net/ListHelp
