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Tensile Instability in a Thick Elastic Body.
Johannes T B Overvelde1,2, David M J Dykstra1, Rijk de Rooij1
1John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Physical Review Letters
|September 10, 2016
Summary
Researchers observed a new elastic tensile instability in soft materials under stretching. This discovery reveals a novel instability phenomenon in elastic bodies, expanding possibilities for smart structure design.
Area of Science:
- Soft matter physics
- Materials science
- Mechanics of materials
Background:
- Soft bodies undergoing large deformations can exhibit various instabilities.
- Previous analytical work predicted tensile instability in elastic blocks under equitriaxial tension.
Purpose of the Study:
- To experimentally observe and characterize the predicted elastic tensile instability in soft materials.
- To investigate the behavior of elastomeric samples under generalized plane strain conditions.
Main Methods:
- Centimeter-scale experiments were performed on thick elastomeric samples.
- Generalized plane strain conditions were applied to induce stretching.
Main Results:
- The elastic tensile instability was observed for the first time in experiments.
- Equibiaxial stretching resulted in the formation of a wavy pattern on the sample surface.
- Regions of the sample alternatively flattened and extended in the out-of-plane direction.
Conclusions:
- This study confirms the existence of an elastic tensile instability in soft materials.
- The findings introduce a new type of instability for elastic bodies.
- This discovery broadens the design potential for smart structures utilizing instabilities.
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