Research On Damage Mechanism Of Aircraft Composite Material And Airworthiness Evaluation Technology

With the development of aviation technology and material science, various of new-style, advanced materials are intensively used in civil aircraft industry. Damage mechanism, failure style and repair technique of composite material are distinct from that of conventional metal material due to its character such as anisotropy. Related technologies such as detection, maintenance and airworthiness certification will thus definitely confront with both development and challenge. How to build a safe, dependable and economical control system has become an urgent problem nowadays. Among these mentioned above, NDI of composite materials is of especial importance.There are four failure modes for laminated composite which are matrix crushing, delamination, fiber tensile failure and debond. After the study of the processing characteristics of composite materials, fatigue and fracture mechanism of composites are theoretically researched, the typical defect of composite and the cause of these defects in civil aircraft are all investigated in this paper. The principle together with the application range of well-known nondestructive testing methods is also studied. The most appropriate test method can hence be determined according to the different category and shape, as well as the failure type of the composite.The defects of the composite are firstly evaluated, the flow of the evaluation on the defects is then established. The repairing methods for the defect and the flow of the repairing can be ascertained subsequently. The database of failure evaluation and repairing are designed which in fact constitute the flow of the airworthiness evaluation. Based on the work done above, airworthiness evaluation system of civil aircraft is finally constructed in this paper.