Buckling folds of a single layer embedded in matrix - Folding behavior revealed by numerical analysis

Theoretical solutions have been proposed recently for various competent layer-matrix systems, including elastic, viscous and elasto-viscous materials. Furthermore, three type fold-forms of buckling fold had been proposed. These solutions were obtained based on the most simplified, one-dimensional governing equations. Therefore, these solutions require further validation by observing the two-dimensional folding behaviors. This work utilizes numerical analyses to study the buckling and post-buckling behaviors of various layer-matrix systems. As a result, it was found that for competence contrast R ≧ 10 the fold-forms obtained by numerical simulation agree well with those theoretical solutions. Three types of fold-forms can be generated and the resulting wavelengths are also close to the predictions. The fold evolution during the post-buckling stage is explored up to high amplitudes, and the results indicate that the fold-forms can remain the same or be changed from one type to another type, depending on the types of layer-matrix system, the applied strain rates, the original fold-forms at buckling, etc. The fold behaviors from buckling to the post-buckling stage of the layer-matrix systems are presented.