Numerical Investigation of Bonded Repair for TDS of Helicopter and Characterization of Kevlar/Epoxy Composite Patch

The tail drive shaft (TDS) of a helicopter is vital component which is responsible for its stability, is often prone to impact damage during combat and is damaged. Usually when the tail drive shaft is damaged, it is replaced during maintenance. But during the time of conflict, the replacement shaft may not always be available. Hence the damaged shaft is patched by a repair technique known as adhesively bonded repair technique or Aircraft Battle Damage Repair (ABDR) technique. In this study, finite element analysis is carried out on the undamaged, damaged, and the patched model of the tail drive shaft, which determines that the deformation, stress and strain in the patched model of the shaft is reduced .Thus, the adhesively bonded repair is an emergency technique that is used to regain the static strength shaft. Mechanical characterization of Kevlar/Epoxy composite material is carried out to choose the apt lay-up sequence for the patch by evaluating its mechanical properties.