Pulsed holographic interferometry: a technique for the detection of structural faults in aircraft structures and computerized recognition of records

摘要

A method of application of pulsed holographic interferometry together with the associated hardware has been developed and applied as a non-destructive inspection (NDI) tool for application to aluminum aircraft fuselages such as those used in the present air transport fleet. A number of novel techniques are involved in the design features of the holographic camera and the method of excitation to obtain optimum conditions where any structural faults present can be made apparent. The holographic camera system has been designed to be small, portable and ruggedly designed so it is suitable for field operations in aircraft repair stations and hangars. The technique operates by the introduction of a selected single frequency vibration signal into the area undergoing test. The camera system has been designed to record both the relative and actual phase of the vibrationally induced into the structure of the fuselage undergoing excitation and NDI. Results are presented showing structural defects. A computerized technique is being developed for the analysis of the interferogram fringe maps an preliminary results are discussed.