Advanced Material Characterization and Structural Certification (AMCSC) Volume 1 of 2
Abstract
Fatigue evaluation and progressive damage growth inspections using X-ray computed tomography (CT) for IM7/5302-1 UNI, IM7/5250-4 UNI, and T650/5320-1 8HS fabric material systems were carried out. Open-hole (OH), interlaminar tension (ILT), double-notch shear (DNS), and short-beam shear (SBS) failure modes were selected for the test program. Tension-tension open-hole fatigue specimens indicated all runouts, even at stress levels (SLs) as high as 90 percent of quasi-static strength. Higher SLs indicated significant amounts of delamination, but minimal damages were noted (microcracks around the hole) for SLs less than or equal to 80 percent. Typical operational conditions for aircraft are significantly less than these SLs, thus tension-tension fatigue is not a concern. Only the ILT failure mode for all three material systems indicated relatively low values of shape parameters, indicating a higher data scatter than the other failure modes investigated in this study. This is primarily due to sensitivity of this failure mode to manufacturing defects in the curved portion of test specimens. The load-enhancement factors (LEFs) calculated for these materials indicate significant reduction due to the improvement in materials and processes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 17, 2020
- Accession Number
- AD1133935
Entities
People
- John Tomblin
- Ruchira Walimunige
- Waruna Seneviratne