Research On Infrared Thermal Wave Nondestructive Detection Technology Of Military Aeroplane

At present advanced composite materials are becoming principal structural material of modern fighter planes, applied to parts such as radar covering, wing, fin, rudder, etc. Nondestructive testing methods on composites of airplane in our country mainly are Ultrasonic and Acoustic impedance methods, which are used to detect metallic structure in many situations. By the look of actual conditions, this method for the detection of composite materials is unsatisfied, for many insufficiencies exist, such as, few damaging measurable, low examining rate, slow measuring, results unable to be backed up, difficult quantitative analysis and so on. Due to great differences between composites and metal in physical property, mechanical property, structural features, manufacturing methods and so on, it is less likely to use those methods to solve all the problems concerning to detect discontinuity or damages in composites of aircraft.In order to meet the present need and solve the practical problems, this paper, based on General Armament Department military scientific research project" the infrared thermal imaging of plane measures technical research ", focuses on the research of infrared thermal wave nondestructive detection technology and project development which are applied to detect composites used in the active service planes.The present study analyses the basic knowledge and theory on infrared ray and infrared imaging inspection technique firstly, and then educes infrared thermal wave nondestructive detection and elaborates its basic theory and technical characteristics. Combined with the actual demand for detecting damage in composite structure of aircrafts in service in outfield situations, an overall project is outlined to develop infrared thermal wave nondestructive detection system of airplane and specific requests on performance parameter are put forward to. Specific requirements on critical components (infrared imaging camera and power supply of flash lamp) are analyzed in detail and an ultimate plan is made about choosing and buying those components according to technical needs. The author has analyzed the overall demand for the application software , made a detailed function and structural design plan, explained and elaborated the concrete function of the main module and design philosophy, designed a algorithm to change infrared hot wave picture into the bitmap, and has realized that changes from the infrared array picture into AVI file on the basis of this algorithm ; besides, the author has introduced the computing technology of the damage area and the damage buried depth of the infrared hot wave picture in detail on the base of the brief illustration to process method of the infrared hot picture.Results of experiment shows the whole detecting system can make specimen producing thermal wave ,can record transformation of temperature on the surface of the specimen, can test the damaged area size and the bury depth accurately . The performance of the system achieves demand of the overall project. In the end, improved measures concerning the existing problems in hardware system and more work plans are proposed.