Award for the Best Scientific Article of the First Quarter of 2023 at the ETSI
The Jury of the Prize for the Scientific Article of the Quarter at the Higher Technical School of Engineering of the University of Seville has awarded the Prize for the Best Scientific Article of the First Quarter of 2023 at the ETSI to the work entitled “Experimental observations of fatigue damage in cross-ply laminates using carbon/epoxy ultra-thin plies” , Composite Structures, vol. 306, February 15, 2023, pp. 116564. DOI: 10.1016/j.compstruct.2022.116564 prepared by Serafín Sánchez-Carmona, Elena Correa, Alberto Barroso and Federico Paris.
The study of the damage mechanisms that occur in cross-ply caused by cyclic loading has aroused great interest in recent years. In parallel, the recent development of ultra-thin sheets has meant that the so-called scale effect , identified in the case of static loads, has acquired renewed importance.
The objective of this work has been to verify if the scale effect also manifests itself in the case of cyclic loading by evaluating its effect on the damage mechanisms known for the case of conventional sheets. To this end, the focus has been on the experimental observation of the appearance of transverse damage and its progression in two different laminates subjected to cyclic tensile-tensile loading.
Firstly, the case of a sequence laminate [0 4 /90 3 /0 4 ] manufactured from sheets with a thickness that can be considered conventional (150 g/m 2 ) has been analyzed, continuing with a laminate [0 4 /90/0 4 ] ultra-thin single layer at 90⁰ (30 g/m 2 ).
All the specimens have been carefully examined using an optical microscope, being able to detect the phases of the damage mechanism expected in the case of laminate of conventional thickness [0 4 /90 3 /0 4 ], carrying out rigorous monitoring of the types of damage and its evolution; In the case of the laminate with an ultra-thin 90º layer [0 4 /90/0 4 ], the same approach has been used, being able to identify similarities and differences with the conventional laminate, including the detection of new types of damage called non-conventional.
One of the most significant results has been the evidence of the delay in the appearance of transverse damage in the 90° layer under cyclic loading, which shows the existence of a scale effect in the development of fatigue damage mechanisms.
