Investigations on axially compressed composite cylindrical shells with surface bonded PZT

Smart materials integrated with thin walled structures can be used to achieve the desired shape, stiffness, damping and other mechanical properties of structures in response to the induced changes in temperature, electric or magnetic field in these, without causing any significant change in the mass as is required in aerospace applications. In this paper, the effects of surface bonded piezo ceramic (PZT-Lead Zirconate Titanate) actuation patches to enhance the strength of thin composite cylindrical shells have been studied experimentally and numerically under the actuation of PZT. The study reveals that it is feasible to minimize the effects of the local imperfections and increase the strength closer to the theoretical buckling strength. However, it has been found that even with the currently available PZTs with minimum thickness, the strength of the tested shell increases owing to the added stiffness of the PZT than due to the actuation. Furthermore, with thinner PZTs of thickness of the order 0.01 times the thickness of the shell and with high actuation force, improvements in the shell capacity is possible by the application of voltage. In addition, the actuation of PZT can be used to decrease the radial buckling deformation for any given load. Importantly, the effect of PZT actuation would increase if the initial imperfections are large leading to larger reductions in the ultimate strength of the shell. Finally, a numerical procedure is established to corroborate the experimental results and also for arriving at an optimum PZT configuration. •The desire for large aerospace structures with low mass.•Thin composite cylindrical shells prone to buckling under axial compression.•Improvement of buckling strength by smart control.•Voltage induced localized moments and tensile membrane stresses by the PZT.