I have seen several questions about ball joints, but none seems to address my need:  I do not want to simulate a ball joint, per se.  I just want to define a contact mechanism between two solid parts that can pivot frictionlessly in any direction (only over a tiny range of angles, because this is a static simulation) but cannot separate or interfere.  (Imagine that the parts are bonded only at a point so are free to rotate but not to translate relative to one another.)

Although I can imagine modeling concentric semi-spherical faces with no-penetration contact conditions between them, this is way too complicated for my application.  I am interested only in static simulation of the rest of a structure when some parts can pivot slightly relative to others.  I am not interested in the stresses or strains at these pivoting joints themselves.

Is there any simple way to do this? -- John Willett