ANALYSIS ON STABILITY CHARACTERISTICS OF QUASI STATIC GROWTH OF A BRIDGED DELAMINATION IN COMPOSITES

In this paper, some new results of axisymmetric post buckling and stability characteristics of growth of a thin film delamination bridged by through thickness fiber tows in a 3D composites are presented. An iterative procedure combined with Taylor's series expansion is used to generate a family of nondimensionalized post buckling solutions of the thin film delamination based on von Karman's nonlinear plate theory. The energy release rate G and the fracture toughness Γ ( ψ , Δ c 1) associated with uniform propagation of a circular delamination are obtained. An important conclusion that the bridge force not only increases the initial growth strain ε * 0 but also obstructs the catastrophic growth of the delamination is drawn from numerical results. In addition, quantitatively the following results are derived: (1) the effect of bridge force on the initial growth of the delamination during post buckling phase, and (2) the regions of stable and unstable growth of the bridged delamination, and (3) the assessment of the range and the dynamic effect of unstable growth for the delamination propagating from unstable to stable.