SENSITIVITY ANALYSIS OF DELAMINATION CHARACTERIZATION IN COMPOSITE TAPERED BEAMS

A composite tapered beam consisting of a S2/SP250 glass/epoxy laminate with (0(2), +/- 45(3))s in the thick section and (0(2), +/- 45(2))s in the thin section is investigated for sensitivity of the interlaminar normal stress and total strain energy release rate at free edge due to variations of taper angle as well as ply angle. Explicit equations of sensitivity analysis for the tapered beam under both tension and bending are formulated. It is found that variation of sigma(z) is more sensitive at the taper root for a given change in the taper angle than at the other locations. However, variation of G(T) is less sensitive. The variation of sigma(z) is less sensitive as the taper angle decreases. For sensitivity due to ply angle variation, it is observed that the outer 0-degrees ply is more sensitive in sigma(z) and G(T) variations than are any other plies. Sensitivity of sigma(z) and G(T) for the tapered beam under a constant curvature was also investigated. Similar trends of sensitivity in these quantities are observed as for the case in tension. However, the degree of sensitivity due to bending is much less.