Evaluating Effectiveness in Bonded Repair Techniques for Aircraft
Structures using Finite Element Simulations
Abstract
Finite element simulations of bonded repair technology can greatly
reduce the cost of repairing ageing and damaged aircraft structures. In
this study, finite element simulation and analysis are performed for
several bonded repair techniques of damaged aircraft structures with
cracks. The simulations start from fatigue damage accumulation, crack
initiation, crack repair, to fatigue crack re-initiation until
structural failure. The effectiveness of bonded repair techniques is
assessed by comparing the service lives of no repair, patch-bonded
repair (live repair), stop-drill repair, and damage removal repair. It
is found that the load attraction by repair patch can greatly sustain
fatigue crack growth, leading to more than at least 2 times longer
service life before the skin structure needs to be replaced. Damage
removal bonded repair can further extend service life by more than 20
times comparing to no repair, benefiting from the fatigue damage
tolerant service life extension. Along with the service life comparison,
we also established a simulation framework that lays out the groundwork
to perform aerostructure bonded repair effectiveness evaluation. The
results demonstrate that finite element analysis can be efficiently used
to simulate the various forms of bonded repairs and effectively evaluate
fatigue crack growth and service life with structural damage. Such a
rigorous simulation framework enables the future design of new repair
techniques for aircraft structures.