Effect of ply orientation and laminate thickness on carbon fibre reinforced polymers under low-velocity impactEinfluss der Gewebeorientierung und Laminatdicke auf kohlenstofffaserverstarkte Polymere unter Stossbeanspruchung mit niedriger Geschwindigkeit

Composite materials, which have gained prominence in the aerospace industry due to their high strength-to-weight ratio, are vulnerable to delamination damage when struck by low-speed projectiles due to their low through-thickness strength. This paper presents the experimental evaluation of a composite plate subjected to low-velocity impact. The plates under discussion were constructed using a carbon fibre reinforced polymer laminate with a quasi-isotropic ply structure. Experiments were carried out using a conical-shaped impactor on carbon/epoxy laminated plates with three different orientations ([0/0] 4 s, [0/90] 2 s, and [45/0-45/90] s) that were put through two distinct impact energies (7 J and 14 J). Impact response is determined using drop-weight impact tests. The techniques of ultrasonic C-scan, field emission scanning electron microscopy (FESEM), and surface micrographs were integrated to provide a new and in-depth understanding of damage evolution and failure mechanisms in composite laminates. Damage resistance appears to decrease as impact energy increases. Furthermore, thicker laminates have lower absorbed energy but, on the other hand, more widespread delamination due to increased bending stiffness. Furthermore, quasi-isotropic laminates outperform in terms of damage resistance and increased energy absorption rates by 8 % to 15 %. The efficacy and logic of the suggested model were shown by a strong connection between experimental results.

Automated summary

Composite materials with high strength-to-weight ratio are susceptible to delamination damage when impacted by low-speed projectiles. This paper presents an experimental evaluation of a quasi-isotropic carbon fiber reinforced polymer laminate subjected to low-velocity impact. The study investigates damage evolution and failure mechanisms using ultrasonic C-scan, field emission scanning electron microscopy, and surface micrographs. The results show that damage resistance decreases with increasing impact energy, while quasi-isotropic laminates exhibit improved damage resistance and energy absorption rates.