Nonlinear Mechanics and Stability Analysis

We develop coupled nonlinear mechanics and finite elements for composite and smart structures undergoing large displacements and rotations. The models capture buckling, post-buckling and multi-stable behavior under combined mechanical, electrical and thermal loads. They also predict how pre-load changes natural frequencies and damping.

1. Buckling and post-buckling of piezoelectric laminates
   • Related Publication(s):
     D. Varelis, D. A. Saravanos, “Coupled Buckling and Postbuckling Analysis of Laminated Piezoelectric Composite Plates with Large Displacement and Stress Nonlinearity”, International Journal of Solids and Structures, 41, 1519–1538, 2004.
     
     D. Varelis, D. A. Saravanos, “A coupled nonlinear plate finite element for thermal buckling and postbuckling of piezoelectric composite plates including thermo-electro-mechanical effects”, Journal of Thermal Stresses, 45(3), 205–228, 2022.
2. Nonlinear shell elements and multi-stable structures
   • Related Publication(s):
     D. Varelis, D. A. Saravanos, “Coupled mechanics and finite element for non-linear laminated piezoelectric shallow shells undergoing large displacements and rotations”, International Journal for Numerical Methods in Engineering, 66(8), 1211–1233, 2006.
     
     D. Varelis, D. A. Saravanos, “Coupled nonlinear mechanics for the electromechanical response of multi-stable piezoelectric shallow shells with piezoelectric films”, Aerospace Science and Technology, 109, 106444, 2021.
3. Vibration and damping under buckling loads
   • Related Publication(s):
     D. I. Chortis, D. S. Varelis, D. A. Saravanos, “Linearized Frequencies and Damping in Composite Laminated Beams Subject to Buckling”, ASME Journal of Vibration and Acoustics, 135(2), 021008, 2013.

Applications

• Stability design of composite panels and blades
• Morphing and multi-stable structures
• Thermally loaded smart structures
• Bistable energy harvesters