Nonlinear delamination buckling and expansion of functionally graded laminated piezoelectric composite shells

• An analytical solution for local buckling and expansion of functionally laminated shells.
• The locally critical loading depends on the geometric angle of delaminations.
• The temperature effect on critical loading depends on the geometric angle of delaminations.
• For some delaminated patterns, the elliptical delamination will expands a circular delamination.

In this paper, an analytical method is presented to investigate the nonlinear buckling and expansion behaviors of local delaminations near the surface of functionally graded laminated piezoelectric composite shells subjected to the thermal, electrical and mechanical loads, where the mid-plane nonlinear geometrical relation of delaminations is considered. In examples, the effects of thermal loading, electric field strength, the stacking patterns of functionally graded laminated piezoelectric composite shells and the patterns of delaminations on the critical axial loading of locally delaminated buckling are described and discussed. Finally, the possible growth directions of local buckling for delaminated sub-shells are described by calculating the expanding forces along the length and short axis of the delaminated sub-shells.

Fig. 1. Comparison of results from two elliptical denominations [P0] and [P0/30°] in FGM laminated piezoelectric composite shells [P0/30°/60°/90°/FGM/90°/60°/30°/P0] under radial electric field Ez and thermal loading ΔT, where Φ = 1, ΔTi = 50 °C, ΔTo = 200 °C and Ez = 2e6 (V/m). Fig. 2. The expanding forces Ga and Gb for local surface delamination are, respectively, along the length and short axis of elliptical delamination, where FGM laminated piezoelectric composite shells [P0/30°/60°/90°/FGM/90°/60°/30°/P0], surface delamination [P0], Φ = 1, ΔTi = 50 °C, ΔTo = 200 °C, Ez = 2e6 (V/m) and hb/R = 0.012.Figure optionsDownload as PowerPoint slide