Large Strain Viscoelastic Material Model for Deformation, Stress and Strain Analysis of O-rings

  • György Szabó Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Hungary
  • Károly Váradii Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Hungary

Abstract

Primary aim of this paper is to investigate the mechanical behavior of an O-ring seal made of NBR rubber material using finite element method. Further aim is to identify the O-ring’s critical locations where it can fail under normal operating conditions. For these a large-strain viscoelastic material model was set up. The recommended strain range where the material model should be sufficient is 0-100 % for normal conditions, but when the effect of overload or the temperature is the question, the strain range should be 0-150 %. From designer point of view, a large-strain viscoelastic material model with a 5 parameter Mooney-Rivlin term is appropriate. To make sure the material model′s accurate response, uniaxial tension, pure shear and equibiaxial measurements are needed, completed with dynamic measurements with a DMTA machine. The results show two critical locations where the failure of the O-ring is expected. One is on the edge of the O-ring near the gap, when friction is present, the other one is under the edge near the gap.

Keywords: Large-strain viscoelasticity, NBR rubber, O-Rings, Numerical Modeling, Finite Element Analysis
Published online
2018-02-26
How to Cite
Szabó, G. and Váradii, K. (2018) “Large Strain Viscoelastic Material Model for Deformation, Stress and Strain Analysis of O-rings”, Periodica Polytechnica Mechanical Engineering, 62(2), pp. 148-157. doi: https://doi.org/10.3311/PPme.11595.
Section
Articles