Plastic contact of self-affine surfaces: Persson's theory versus discrete dislocation plasticity

S. P. Venugopalan, N. Irani, L. Nicola*

*Corresponding author for this work

    Research output: Contribution to journalArticleScientificpeer-review

    11 Citations (Scopus)
    66 Downloads (Pure)


    Persson's theory allows for a fast and effective estimate of contact area and contact stress distributions when a flat and a self-affine rough surface are pressed into contact. For elastic bodies, the results of the theory have been shown to be in very good agreement with rather costly simulations. The theory has also been extended to plastic bodies. In this work, the results of Persson's theory for plastic bodies are compared with those of discrete dislocation plasticity. The area–load curves obtained by theory and simulations are found to be in good agreement when the rough surface has a very small root-mean-square (rms) height. For larger rms heights, which are more realistic for metal surfaces, the agreement is no longer good unless in the theory, instead of a size-independent material strength, one uses a rms height- and resolution-dependent yield strength. A modification of this type, i.e., the use of a yield strength dependent on size, does however not lead to agreement between the probability distributions of the contact stress, which is much broader in the simulations than in the theory. The most likely reason for this discrepancy is that the theory, apart from neglecting plasticity size dependence, only applies to elastic-perfectly plastic bodies and therefore, neglects strain hardening.

    Original languageEnglish
    Article number103676
    Number of pages13
    JournalJournal of the Mechanics and Physics of Solids
    Publication statusPublished - 2019


    • Contact mechanics
    • Dislocation dynamics
    • Persson's theory
    • Plasticity
    • Self-affine surfaces


    Dive into the research topics of 'Plastic contact of self-affine surfaces: Persson's theory versus discrete dislocation plasticity'. Together they form a unique fingerprint.

    Cite this