What are common manufacturing defects in composite structures and how are they detected?

Common composite defects include: Porosity (voids from trapped air or volatiles), Delamination (separation between plies), Foreign object inclusion (release film, backing paper), Fiber waviness (misaligned or wrinkled fibers), Resin-rich/dry areas (improper resin distribution), and Cure anomalies (under-cure, over-cure). Detection methods: Ultrasonic inspection (C-scan for delamination, porosity), Radiography (FOD, fiber misalignment), Thermography (subsurface defects), Visual inspection (surface defects), and Tap testing (disbonds). Defect acceptance limits are defined in specifications; beyond limits requires disposition through analysis, repair, or rejection. Manufacturing process control prevents defects.