The purpose of this project is to develop a damage tolerance methodology and associated programs (or software) for the evaluation of 4 classical 3D metallic structures.
To ensure the analytical methodology and program (or software) can be successfully reviewed and accepted by CAAC, at least one structural and stress DER of FAA should be responsible for the technical development of this project.
Finish the relevant work established by the methodology of damage tolerance analysis of 3D metal structures for 4 classical structures. The research results shall meet the following requirements:
Based on the structures of other aircrafts and referring to their own engineering experience, to sort out the types of structures and details (such as the cockpit windshield frame, the door frame stopper, and the connecting joint at the floor beam of the fuselage frame, the main landing gear joint, etc.) to list in the Structure Classification Report.
Regarding the four classical structure details, to develop the 3D damage tolerance methodology research. The four classical structures are listed in Fig 1:
Lugs (single lug, fork lug, and cantilever lugs of different geometries);
Radius area of parts (the root area and gap area of lug joints);
Connecting parts with obvious 3D geometry like the joint fittings connecting outer wing and center wing box;
Thick parts (machined forged frames of mid-fuselage, the stress on the inner flange is so big which easily cause edge crack.