Fractal Surface Generator

This is a MATLAB App for the randomisation of surface roughness with specified height-probability distribution (HPD) and spectral content.

In this MATLAB App we present a simple method to generate surface topography. The main advantage of the presented method as compared with those available in the literature is that the power spectrum and the height probability distribution can be specified independently. In this article [1] we present the method and show its versatility by generating surface topographies with three different height probability distributions: the Weibull distribution, a bimodal distribution and a distribution containing a delta function that represents worn surfaces. And in this article [2] the method is used to investigate the stiffness of surfaces with non-Gaussian height distributions by means of using Boundary Element Method (BEM) described in [3], with the elastoplastic approximation that is described in [4].

[1] Pérez-Ràfols, F. & Almqvist, A. (2019). Generating randomly rough surfaces with given height probability distribution and power spectrum, Tribology International, 131, 591–604. https://doi.org/10.1016/j.triboint.2018.11.020

[2] Pérez-Ràfols, F., & Almqvist, A. (2021). On the stiffness of surfaces with non-Gaussian height distribution. Scientific Reports, 11. https://doi.org/10.1038/s41598-021-81259-8

[3] Almqvist, A., Sahlin, F., Larsson, R., & Glavatskikh, S. (2007). On the dry elasto-plastic contact of nominally flat surfaces. Tribology International, 40(4), 574–579. https://doi.org/10.1016/j.triboint.2005.11.008

[4] Sahlin, F., Larsson, R., Almqvist, A., Lugt, P., & Marklund, P. (2010). A mixed lubrication model incorporating measured surface topography: Part 1: theory of flow factors. Proceedings of the Institution of Mechanical Engineers. Part J, Journal of Engineering Tribology, 224(4), 335–351. https://doi.org/10.1243/13506501JET658