Stage 1 : The Material Preparation task utilizes Ansys
Engineering Data tool [20] to prepare necessary material properties
such as stiffness, strength, fatigue S-N properties, Paris Law, etc. TheGeometry Preparation task utilizes Ansys SpaceClaim geometry tool
[20] to import/create wing plank, crack, and repair patch
geometries;
Stage 2 : During Mesh Generation task high quality finite
element mesh is generated on prepared wing plank and repair patch
geometries in Ansys Mesher tool [18], as well as to produce crack
mesh. The Model Setup task is done through Ansys Mechanical tool
[18], in which the practical loads and constrains are applied on
wing plank structure, connecting repair patch, etc.;
Stage 3 : The Fatigue Damage Analysis quantifies the
fatigue damage accumulation in estimating crack initiation. It utilizes
the Fatigue Tool capability in Ansys Mechanical to predict the
repaired structure’s extended service life before new crack initiates in
repair techniques with crack tip treatments such as stop-drill or
damage-removal. The Crack Propagation Analysis task will analyze
the crack growth under fatigue loading, using the Fracture tool and
SMART Crack Growth capabilities in Ansys Mechanical. The task produces
the relationship between service loading cycles and crack advance
quantity for unrepaired or repaired fatigue crack service life
estimation.