Effects of axial impacts at different temperatures on failure response of adhesively bonded woven fabric glass fiber/epoxy composite joints

Evaluating post-impact failure responses of single-lap adhesively bonded composite-to-composite joints in uniaxial static tensile loading was the main objective of the current experimental study. At first, axial tensile impacts having various energy levels (10, 15, 20, and 25 J) were applied to the joints at different temperatures (−20, 0, room temperature, 50, and 80℃). Afterward, the samples were secondarily subjected to static tensile loading at ambient temperature, so that reductions in joint strengths arising from the impacts performed under different loading conditions could be assessed. Consequently, it was definitely proved that each of the axial impacts performed in any loading case has a noticeable effect on ultimate joint strengths, proportionally to the acting condition. Besides, the combination of high energy and temperature sometimes appeared to be the reason of impact failure, which occurs instantly without being able to perform axial static tests. When applied energy and/or absolute difference from room temperature is increased, lower joint resistances could be measured during secondary tensile tests.