TY - JOUR
T1 - Influence of layup, stacking sequence and loading rate on energy absorption of tension-absorber joints
AU - Hassan, Jazib
AU - O'Higgins, Ronan M.
AU - Feser, Thomas
AU - Waimer, Matthias
AU - McCarthy, Conor T.
AU - Toso, Nathalie
AU - McCarthy, Michael A.
N1 - Publisher Copyright:
© 2020 The Author(s)
PY - 2021/4/1
Y1 - 2021/4/1
N2 - “Tension-absorber” joints are bolted joints designed to absorb energy in a survivable crash landing, through an extended version of bearing failure. They have been proposed for use in future transport aircraft narrow-body composite fuselages. Herein, the influence of layup (percentage of each ply orientation), stacking sequence (exact location of each ply) and loading rate, on energy absorption is examined. Quasi-static and dynamic (3 m/s) tests are performed on pin-loaded IM7/8552 carbon-fibre/epoxy laminates. Seven layups and 11 stacking sequences are tested, with key variables being the percentage of 0° plies (from 12.5% to 62.5%), the position of the 0° plies, and the changes in orientation at ply interfaces. Performance measures include ultimate bearing strength (UBS), mass-specific energy absorption (SEA) and crush load efficiency (CLE). Computed tomography is used to examine damage progression in the quasi-static tests. It is found that the most important factor in maximising SEA is having small changes in orientation at ply interfaces. This is even more important than 0° content. A laminate with only 12.5% 0° plies, performed remarkably well due to its low changes in ply orientation. Laminates with a high SEA tend to have a low UBS. Highest UBS was for quasi-isotropic laminates. Increased loading rate results in increased UBS but decreased SEA. The results allow selection of a stacking sequence with a desired combination of UBS and SEA, and provide a valuable database for validation of composites damage models.
AB - “Tension-absorber” joints are bolted joints designed to absorb energy in a survivable crash landing, through an extended version of bearing failure. They have been proposed for use in future transport aircraft narrow-body composite fuselages. Herein, the influence of layup (percentage of each ply orientation), stacking sequence (exact location of each ply) and loading rate, on energy absorption is examined. Quasi-static and dynamic (3 m/s) tests are performed on pin-loaded IM7/8552 carbon-fibre/epoxy laminates. Seven layups and 11 stacking sequences are tested, with key variables being the percentage of 0° plies (from 12.5% to 62.5%), the position of the 0° plies, and the changes in orientation at ply interfaces. Performance measures include ultimate bearing strength (UBS), mass-specific energy absorption (SEA) and crush load efficiency (CLE). Computed tomography is used to examine damage progression in the quasi-static tests. It is found that the most important factor in maximising SEA is having small changes in orientation at ply interfaces. This is even more important than 0° content. A laminate with only 12.5% 0° plies, performed remarkably well due to its low changes in ply orientation. Laminates with a high SEA tend to have a low UBS. Highest UBS was for quasi-isotropic laminates. Increased loading rate results in increased UBS but decreased SEA. The results allow selection of a stacking sequence with a desired combination of UBS and SEA, and provide a valuable database for validation of composites damage models.
KW - Composite bolted joints
KW - Energy absorption
KW - Micro CT analysis
KW - Stacking sequence
UR - http://www.scopus.com/inward/record.url?scp=85097458181&partnerID=8YFLogxK
U2 - 10.1016/j.compstruct.2020.113327
DO - 10.1016/j.compstruct.2020.113327
M3 - Article
AN - SCOPUS:85097458181
SN - 0263-8223
VL - 261
JO - Composite Structures
JF - Composite Structures
M1 - 113327
ER -