Volume 129, Number 4, February 2020
|Number of page(s)||7|
|Section||Condensed Matter: Structural, Mechanical and Thermal Properties|
|Published online||18 March 2020|
Pattern formation on free surfaces via plastic buckling and periodic folding
1 Center for Materials Processing and Tribology, Purdue University - West Lafayette, IN, USA
2 Department of Mechanical Engineering, Indian Institute of Science - Bangalore 560012, India
Received: 3 January 2020
Accepted: 28 February 2020
Spontaneous formation of surface patterns such as folds and creases is widely observed in engineered systems, such as thin films and machined surfaces, as well as in natural systems such as floral petals and leaves. A recognized route for their formation is via surface elastic instabilities. Here we demonstrate an alternate route for their formation —plastic buckling and folding—that occurs when ductile materials are subject to large-strain (>1) deformation. Using in situ imaging of simple-shear deformation of polypropylene, we delineate the mechanics underlying formation of folds and the resulting surface morphology. The fold pattern shows a single wavelength that scales linearly with the size of the plastic zone. An analytical model predicts onset of the plastic buckling instability and characteristics of the folds. Besides obvious applications for controllably generating surface features over large areas, our results suggest a contributing mechanism for origin of surface roughness in solids.
PACS: 62.20.-x – Mechanical properties of solids / 61.82.Pv – Polymers, organic compounds / 05.65.+b – Self-organized systems
© EPLA, 2020
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.