Hi,

I'm having quite an annoying problem. I'm modelling two steel bars impacting on each other. One bar is meshed with solids and the other one with SPH elements. When I use general contact, everything works fine. But when I want to do the same with contact pairs (with the kinematic constraint or even with the penalty method), a warning occurs:

"The nodes contained in node set WarnNodeContPairZeroMass belong to a contact pair surface but have zero mass. Contact constraints may not be enforced correctly at these nodes."

The set refers to the SPH mesh. The simulation aborts very soon after contact, with a severe distortion in the solid mesh. The surfaces are the same as with the general contact and the manual says that contact pairs can be used as well with SPH, so, I don't see what's going wrong. Does anyone has an idea?

Kind regards,

Frederik