Research Of Ultrasonic Testing Technology For Carbon Epoxy Composite Pipe And System Development

Carbon fiber reinforced resin matrix composite materials (hereinafter referred to ascomposite materials) play an important role in the aerospace field because of its manyadvantages. In the course of the development of new launch vehicles, the research ofthrust component using composite pipe is in progress. The composite pipe used to beara large load in axial compression and tensile force is the important components on thelaunch vehicle. Composite pipe use wet winding, low speed rotary curing. With highporosity, sound attenuation, and the characteristics of small diameter with large length,methods of nondestructive testing commonly used in this composite pipe are notapplicable at present. According to the tubular parts, this paper put forward themethod of echo from a board to detect the internal quality of composite pipes, andcarried out an ultrasonic automatic C-scan system which could achieve the detection ofproducts. The main work as follows:1) Based on the production technology of composite pipe, this paper analysis anddetermine the composite pipe internal defects that may exist, main characteristics and itscauses.2）According to the service environment of the composite pipe and its productionprocess, the author cooperate with design and production department to determine thesensitivity requirements of nondestructive testing to the composite pipe.3) On the basis of the research on nondestructive testing of composite materials indomestic and abroad, so the paper conducts experimental research and technicalanalysis of the application possibilities of the various ultrasonic methods.4) The method of echo from a board is the first proposed which is based on theultrasonic reflection signals of inner wall of the pipes. Designed and fabricated anumber of organic glass pipe samples. According to different size of these samples,some related tests were made such as the eccentricity of non-focus probe, focus probe,water from the focal length. And the correlation analysis provides a theoretical guidancefor the detection.5) This paper carried out the system development of the method of echo from aboard to the composite pipes.6）The ultrasonic testing method of composite pipe quality was researched anddeveloped. 7) The author conducted the actual testing on composite pipes.The results of the study show that the method of echo from a board is a kind ofhigh reliability, high sensitivity ultrasonic testing method to composite pipe which ishigh porosity, sound attenuation, and the characteristics of small diameter with largelength.And the method can accurately detect the internal stratification, loose, porosityand other defects of the sample.