Using nondestructive testing methods to characterise production-induced defects in a metal-CFRP hybrid structure
In this work different nondestructive testing methods, such as active and passive thermography as well as ultrasonic with special probes, so-called EMAT`s (ElectroMagnetic AcousticTransducer) will be applied for the characterisation of a metal-CFRP (Carbon Fibre Reinforced Polymer) hybrid structure. To validate these testing methods, different kinds of artificial defects are inserted into the hybrid structure. It is shown that active thermography is very suitable to detect the artificial inserted defects not only in the hybrid structure but also in the CFRP structure itself. Furthermore the bonding between metal and the polymer is characterised very well. Likewise CFRP samples are investigated by passive thermography while being mechanically loaded through tensile or fatigue tests to give a predication about the influence of the defects on the mechanical properties (effects of defects).Finally an outlook on an optimised geometry of the hybrid structure as well as on further excitation methods for active thermography is given.