Berlin 2008 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 29: Poster II
DY 29.33: Poster
Donnerstag, 28. Februar 2008, 16:00–18:00, Poster C
Desiccation cracks on different substrates: simulation by a spring network model — Supti Sadhukhan2, Dibyendu Mal2, Sujata Tarafdar2, Tapati Dutta3, Karl Heinz Hoffmann1, and •Janett Prehl1 — 1Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz — 2Condensed Matter Physics Research Center, Jadaypur University, Kolkata 700 032, India — 3Physics Department, St Xavier’s College, Kolkata 700016, India
Crack patterns formed due to desiccation of clay or similar materials show distinctive reprocucible patterns [1]. Plotting the cumulative area Acum covered by the cracks versus their width ≥ Wmin a typical reproducible shape can be seen. In a log-log plot, this curve has two roughly linear regions with different slopes. For a ploypropylene substrate, there is a sharp change from a nearly horizontal line to a very steep line [2], whereas for a glass substrate, which is smoother, there is a gradual changeover between the two regions [3]. We propose a simple 1d and 2d spring chain model, in which reducing the natural length of the springs corresponds to the desiccation process. Springs may break, or slip over the substrate to accommodate strain beyond a specified threshold. The model successfully reproduces the successive stages of crack formation and behaviour of the cumulative area curve, as observed in experiments.
[1] D. Mal, et al., Appl. Clay Sci. at press, doi:10.1016/j.clay.2007.05.005
[2] D. Mal, et al., Fractals, 14, 283 (2006)
[3] D. Mal, et al., J. Phys. Soc. Japan, 76, 014801 (2007)