Understanding Conductivity in Complex Contact Interfaces

Recent research conducted by Paul Beguin and Vladislav A. Yastrebov focuses on the electrical and thermal conductivity of complex-shaped contact spots. The study employs an in-house Fast Boundary Element Method to analyze various geometries, beginning with annulus contact spots to evaluate the impact of connectedness. The researchers then explore the shape effects on multi-petal contact spots, which exhibit dihedral symmetry and resemble flowers, stars, and gears. The analysis culminates with self-affine shapes, representing a multiscale generalization of the multi-petal forms.

In their findings, the authors introduce appropriate normalizations and develop phenomenological models. For the multi-petal shapes, the model is based on a single geometric parameter: the normalized number of petals. This approach inspired the phenomenological model for self-affine spots, which relies on four geometric characteristics: standard deviation, second spectral moment, Nayak parameter, and Hurst exponent. The study also suggests flux estimations for an infinite number of petals and the fractal limit.

This research represents a significant step toward understanding the conductivity of complex contact interfaces, which are commonly encountered in the contact of rough surfaces. The implications of this work could extend to various applications in materials science and engineering, particularly in optimizing the performance of devices that rely on effective thermal and electrical conductivity.

The full paper can be accessed at arXiv:2311.14854.