Seminar Schedule – Spring 2017

Tuesday, April 11, 2017
Time: 3:30-5:00 PM
Place: WRW 102

Ruga Mechanics of Soft Materials

Mazen Diab – UT Austin

In recent years, researchers have studied principles of structural instabilities of soft materials with the aim to design multifunctional materials with controllable surface ruga-patterns. In principle, ruga-patterns, such as wrinkle, crease, fold and ridge can form on the surface of soft materials under large deformation as a result of structural instability. However, to harness these ruga-patterns for controllable functionality, it is essential to understand and quantify not only their formations but also transitions among them. In the first part of this talk, I will show how through applying mathematical principles of nonlinear bifurcation, we could quantify the initiation of crease instability. I will demonstrate that crease may be triggered at the surface of elastomers by a cascade of wrinkle instability of infinite orders (instantaneous crease), or of finite orders (setback crease). In the second part of this talk, I will show how through a hybrid analytical and numerical approach, we could map all the admissible ruga-patterns on the surface of a neo-Hookean bilayer-system under compressive loading. A phase-diagram that encompasses all the possible ruga-patterns and transition paths among them will be presented and its implication on designing multifunction material structures will be discussed.

For further information, please contact Dr. K. Ravi-Chandar at ravi@utexas.edu or (512) 471-4213.