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Actual Processes and Researches at Eurocopter on Failure Investigation of Metallic and Composite Parts
Last modified: 2013-05-03
Abstract
Eurocopter's approach on parts Failure Analysis is presented for both Metallic and
Composites. Actual processes: For Metallics, nature of the failure (Fatigue/Static
Progressive/Brutal) is determined from part deformation, grain flow & fracture
surfaces (macro/micro scale, SEM/TEM). Compared with stress calculations
(direct or reverse), it enables to confirm scenario of ruin. For Composites, same
methods are less convincing and it's often difficult to determine type of rupture:
Broken parts have only little (or no) deformation; Ruin process is diffuse; Failure
often crushes fracture surfaces. Researches are conducted to reduce cost & time
on failure analysis process. For Metallics they concern: da/dN measurement by
topography; beach mark interpretation; SIF calculation of 3D cracks with contact.
For Composites, recent progresses allow to estimate: Damage zones & levels;
Failure initiation loads. Combining prediction with 3D observation, and thanks to
high resolutions reached from small size sources, new investigation methodology
for composite parts can be envisioned.
Composites. Actual processes: For Metallics, nature of the failure (Fatigue/Static
Progressive/Brutal) is determined from part deformation, grain flow & fracture
surfaces (macro/micro scale, SEM/TEM). Compared with stress calculations
(direct or reverse), it enables to confirm scenario of ruin. For Composites, same
methods are less convincing and it's often difficult to determine type of rupture:
Broken parts have only little (or no) deformation; Ruin process is diffuse; Failure
often crushes fracture surfaces. Researches are conducted to reduce cost & time
on failure analysis process. For Metallics they concern: da/dN measurement by
topography; beach mark interpretation; SIF calculation of 3D cracks with contact.
For Composites, recent progresses allow to estimate: Damage zones & levels;
Failure initiation loads. Combining prediction with 3D observation, and thanks to
high resolutions reached from small size sources, new investigation methodology
for composite parts can be envisioned.
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