Experimental Study on Low‐Velocity Impact and Compression After Impact of Hybrid Composite Laminates Based on the Winding Angles of Composite Cylinders

ABSTRACT Carbon fiber–reinforced polymer (CFRP) laminates are structurally sensitive to impact behavior, so impact resistance is one of the most critical mechanical properties of fiber‐reinforced composites. The cylinders typically incorporate co‐cured glass fiber layers on the carbon fiber surfaces, but existing research on composite cylinders has failed to account for the influence of these surface glass fiber layers. To provide guidance for impact damage assessment of composite cylinders, this study designed hybrid carbon/glass fiber composite laminates with optimized winding angles. Low‐velocity impact tests and compression‐after‐impact tests were conducted at three energy levels (40, 60, and 80 J). Post‐impact delamination was detected through ultrasonic C‐scan imaging, and three‐dimensional digital image correlation (3D‐DIC) was employed to record strain field changes during compression. Microscopic damage was characterized by using scanning electron microscopy (SEM) and optical microscopy. C‐scan results show that different types of hybrid laminate achieved varying degrees of delamination area reduction. Taking GP‐FF laminate as an example, the delamination areas decreased by 11.0%, 12.8%, and 15.9% under the three impact energy levels (40, 60, and 80 J), respectively. Observation of post‐impact damage morphology revealed that under 40 J impact energy, the visual damage areas of 0.6, 1.2, and 1.8 mm glass fiber layers increased by 302%, 1718%, and 2252%, respectively. Under relatively low‐energy impacts, hybrid laminates have slightly higher residual strength than pure carbon fiber (CP) laminates. However, as impact energy increases, CP laminates exhibit superior residual strength.