Elastic instability, long considered mainly as a failure limit state or a safety guard against ultimate failure is gaining increased interest due to the development of active and controllable structures, and the growth in computational power. Mode jumping, or snap-through, during the postbuckling response leads to sudden and high-rate deformations due to generally smaller changes in the controlling load or displacement input to the system. A paradigm shift is thus emerging in using the unstable response range of slender structures for purposes that are rapidly increasing and diversifying, including applications such as energy harvesting, frequency tuning, sensing and actuation. This paper presents a finite element based numerical study on controlling the postbuckling behavior of fiber reinforced polymer cylindrical shells under axial compression. Considered variables in the numerical analyses include: the ply orientation and laminate stacking sequence; the material distribution on the shell surface (stiffness distribution); and the anisotropic coupling effects. Preliminary results suggest that the static and dynamic response of unstable mode branch switching during postbuckling can be fully characterized, and that their number and occurrence can be potentially tailored. Use of the observed behavior for energy harvesting and other sensing and actuation applications will be presented in future studies.
EXPERIMENTAL AND NUMERICAL STUDY OF DEFECTS IN PRESSURESED CYLINDRICAL SHELLS INSTRUMENTED BY ACOUSTIC EMISSION AND STRAIN GAUGES
