A numerical fatigue delamination model is validated by means of experimental tests. Delamination is initiated on the skin-stiffener interface which, under cyclic compressive loading and in the post-buckling regime, grows at a decreasing rate. A cohesive zone formulation is used to model the static and fatigue delamination growth, good agreement is found in terms of delamination shape. Further investigation is required, using improved material inputs, for the model to be validated in terms of delamination magnitude. The numerical model shows promising characteristics, which may be employed for future damage tolerant composite structural designs.

This report is the final report in a series of four reports that deals with the design of an advanced regional aircraft. The first step in the design is to determine the overall configuration of the ARA. By identifying the feasible configurations based on a literature study and performing a trade-o_, the conventional low wing with GTF engines underneath the wings configuration is found to be the optimal configuration for the ARA. After selecting the aircraft configuration, the preliminary subsystem design is initiated. Class I and II weight estimations are performed and a MTOW of 34500kg is determined. The selected wing planform is a two-piece complex sweptback planform with a wing area of 105m2 and a wing span of 30.7m. The thrust will be provided by two PW1217G GTFs with a maximum thrust of 76kN each. For the fuselage design, several configuration options are analysed taking into account structural and aerodynamic considerations. A trade-o_ is performed and the 4 abreast configuration with cargo in the tail is found to be the best choice. The tricycle configuration is chosen for the landing gear. The main gear is positioned 17.1m from the nose, while the nose gear is positioned 3.6m from the nose. The control surfaces comprising ailerons, spoilerons, elevators and rudder, are sized for extreme load cases. For roll control at low speeds outboard ailerons are used and spoilerons are used for roll control at high speeds. The elevators are sized to meet take-o_ and trim requirements. The rudder is sized to counteract the yawing moment with one-engine inoperative. Furthermore, the high-lift devices are sized. It is found that in order to fulfill landing and take-o_ requirements double-slotted Fowler flaps are required...