Torsional shear strength of steel joined with high performance aerospace adhesives at cryogenic and elevated temperatures

Abstract

Pure torsional shear tests of joints glued with two different aerospace grade adhesives were performed using a specifically designed and constructed torsional shear test equipment. The developed test equipment allows for measuring of pure torsional shear strength under cryogenic and at elevated temperature conditions. The adhesives Hysol EA 9321 and 3M Scotch-Weld EC-9323-2 B/A were used to join steel torsional shear test specimens. Torsional shear tests were performed from -180°C to 150°C. In addition torsional shear fatigue tests were also performed at various loads and the effect of cryogenic aging (cyclic cooling and warming) on the torsional strength of the joints was investigated. The results showed that both sets of adhesive joints achieved three times higher torsional shear strength at -180°C compared to room temperature.

A review on the environmental degradation effects on fatigue behaviour of adhesively bonded joints

“…They developed an accurate numerical model to predict the fatigue life at elevated temperatures using (i) the ratio of the static shear strength at RT and at high temperature and (ii) the parameters obtained from the stress‐life (S‐N) curves at RT. Blugan et al 22 designed and built a torsional shear strength equipment to perform tests at cryogenic and at elevated temperatures. The authors tested steel joints bonded with two different aerospace adhesives under extreme temperatures of −180°C and 150°C.…”