A method is disclosed for testing for delamination of a first composite component from a second composite component a composite material. The method comprises coupling a broad-band actuator to the composite material and connecting sweeping frequencies to the broad-band actuator for vibrating the composite material. An acoustic sensor is coupled to the composite material for measuring a resonant frequency curve of the vibrating composite material. The measured resonant frequency curve of the vibrating composite material is compared with a reference resonant frequency curve. A delaminated composite material produces a change in the measured resonant frequency curve relative to the reference resonant frequency curve. The method is suitable for detecting delamination in fuel cells as well as ceramic body armor.