We will show that in multilayer viscoelastic structures, viscoelasticity affects not only the transient phenomena in the development of deformation patterns, but also the final deformation pattern. Thus, for the prediction of the final deformation pattern, the elastic theory in the limit of viscoelastic material properties when $ t to infty $ is not enough, and the analysis of the entire evolution of the deformation pattern is necessary. The results of the proposed project will provide:
i) understanding of the evolution of deformation in multilayered viscoelastic structures,
ii) new computational methods for predicting the development of these deformation patterns; and
iii) enable the development of new innovative methods for the fabrication of smart (wrinkled) surfaces for advanced functionalities.
The key project phases are:
a) development of analytical tools
We will first develop a toy model that will provide a qualitative understanding of the evolution of the deformation pattern due to wrinkling of thin elastic films on a soft viscoelastic substrate. We will use it to describe the dynamic formation of wrinkles on the sample and their development towards the final deformation pattern.
b) development of numerical tools
We will also develop a theory that describes the temporal viscoelastic response of real multilayer structures to different temporal loading functions. To solve these generalized theories, we will use the finite element method and special methods for solving numerical systems.
c) simulations of given problems
We will discuss problems such as: wrinkling of coatings during drying, wrinkling of polymer composites during swelling, etc.
d) experiments:
We will characterize the viscoelastic behavior of polymer mixtures and conduct a series of desktop experiments to evaluate the toy and full model.
e) dissemination, writing reports, scientific papers
