Surface wrinkles and local bifurcations in elastomeric components: seals and gaskets. Part I. Theory

Abstract

This two-part paper develops schemes to handle the analysis of elastomeric components (seals, gaskets), undergoing large deformations leading to potential surface folding-wrinkling-stretching, as well as localized bifurcations. Since significant element degeneracies occur in the vicinity of such behavior, specialized procedures are developed to define the ensuing deformation morphology. For instance, this includes the modelling of the complex mechanical fields in the apex region of the folding collapse zone along with the associated self contact. The checks monitor local-global system stability, solution conditioning, as well as kinematic motion leading to self-contact in wrinkle zones. These initiate the concomitant remesh cycle. To generalize the results, the eigenvalue properties of the tangent stiffness are formally investigated. Here the main emphasis is to define the occurrence of shifts in definiteness leading to bifurcations on the element, regional and global levels. Part II will benchmark the scheme.