Evaluation of O-ring stresses subjected to vertical and one side lateral pressure by theoretical approximation comparing with photoelastic experimental results

Contact and internal stresses of an elastomeric O-ring which is subjected to a vertical compression and lateral pressure at one side are evaluated experimentally and theoretically for a failure analysis and a life prediction. In the experiment, the O-ring specimen was made of epoxy resin. The applied fractional compression was 20% and the lateral pressure was varied as 1.96, 2.94 and 3.92 MPa. The photoelastic experimental hybrid method was used to obtain both the contact and internal stresses. To develop a theoretical approximation method for the stresses, the contact length and peak stress were evaluated by the conventional Hertz theory. It was found that the correction factors could resolve the difference between the experimental and theoretical results. In turn, the internal stress was evaluated by using the Flamant theory and a numerical approach. The pattern and values of the experimentally and theoretically obtained internal stresses also coincided well with each other.