Research Information System
Composite Structures, vol.357, 2025 (SCI-Expanded)
Specific requirements in aircraft components may necessitate the use of high taper angles in the thickness transition region of composite laminates, leading to early delamination initiation at the thin side of the taper region. This study demonstrates that nonlinear taper geometries could significantly delay delamination in highly tapered laminates. A method is proposed to define the taper geometry with a single design parameter, and the effectiveness of the proposed variable taper angle design, a nonlinear taper geometry, on delamination is demonstrated. Delamination analysis is performed utilizing cohesive elements by incorporating the compression-induced shear enhancement effect. Finite element model is validated through a comparison of the numerical results with the experimental results of single-stage ply drop-off specimens. This study revealed that by utilizing the variable taper angle design, the thin section delamination can be delayed by reducing the stress concentrations in the taper region. For tapered laminates with the particular multi-stage ply drop-off configuration investigated, the proposed concept provided a 35% increase for GFRP laminates and an 81% increase for CFRP laminates in the delamination onset load with the proper choice of the taper angle increment.