Mechanical Behavior of O-Rings

Abstract

Abstract O-ring deformation is approximated as a plane strain contact problem. An integral equation is written for the contact stress which is solved for small deflections. The contact area agrees with the results of the conventional Hertz theory. The displacements of the deformed o-ring are found by requiring zero displacement at the center of the circular cross section. Experimental results on silicone rubber cylinders and o-rings agree with the theory up to approximately 15 per cent strain. A linear viscoelastic solution is constructed from the elastic solution for an o-ring held at fixed deflection for t > 0. For this case the contact area remains constant and the average load is proportional to the relaxation modulus.