Residual capacities of uniaxially compressed, delaminated composite panels

Abstract

The mechanical buckling and postbuckling behaviour of a delaminated panel under uniaxial compression is investigated using a semi-analytical geometrically nonlinear panel model. A Rayleigh-Ritz procedure based on trigonometric displacement functions is used in conjunction with minimum energy principles to ascertain the mechanical response of the panels. The model includes the effect of delamination propagation resulting from the buckling of the laminates utilizing a discrete cohesive zone model. With the model developed, a detailed assessment of the residual capacity of the panel is provided due to its capability of tracing the equilibrium paths far into the postbuckling range.

Nonlinear failure mechanisms of laminated composites

“…Work done from dilation U D and shearing U S can thus be evaluate. Additional features from the original model include strain energies from bending U b and direct compression U m , and the work done from the external load P ∆ can be incorporated without significant alterations, leading to the total potential energy of the system: A previously derived delamination model [3,5] is investigated further for delaminations of size a = b = 20mm. Essentially, the behaviour is very similar to the original case of a = b = 15mm since thin-film buckling also leads to stable delamination growth (Fig.…”

“…A discrete pilot model is currently being developed adapting an existing model for this phenomenon in geological layers [4] such that it can be applied to unidirectional laminated composite struts. Furthermore, additional results are presented from previous investigation on interply damage in flat, plated components [3].…”