Degradation Elements Analysis Of Digital Radiographic Image

Industrial radiographic testing technology, which as a kind of safe,high-efficiency,reliable NDTtechnologies, has been implemented in a lot of industrial and national defence areas, especially in theproduct quality testing of weapon and aviation aspects which needs high requirements, the radiographictesting technology is playing more important role in above areas. in order to analyze the degradationelement of radiographic image according to the feature of radiographic imaging and each part of theimaging system, also studied the physical foundation of radiographic imaging and the structure of imagingsystem. This thesis analyzed the degradation elements which in result from x-ray source and imaging partsrespectively, and the system's degradation elements is also analyzed, considering the degradation elementsare complicated which influence the image quality, the thesis proposed the approach of virtual radiographicimaging system based on MDO technology, the corresponding models have been constructed by use ofmathematical modeling methods, and furthermore, the thesis designed a virtual image generator based onthese models, Finally how to optimize parameters of the model in the virtual experiments has beendiscussed, in this way can the virtual experiments accord with the real physical process precisely.The thesis analyzed the principle of the radiographic imaging and it's structure firstly, the degradationelement in the process of imaging has been studied, when analyzing the degradation element of x-raysource, the source size and radiation intensity distribution are analyzed together. and when analyzing thedegradation element of imaging parts, the vignetting effect of lens and the inconsistent transformingresponse of the transforming flat are analyzed as well, which resulted to the trend factor of radiographicimage. The degradation element of flat panel detector has been studied integrate with the experiments.Finally according to he feature that digital radiographic system is based on multidisciplinary, togetherwith the theory and the experiments of the imaging system. The approach of using MDO(MultidisciplinaryDesign Optimization) to synthesize analysis of the degradation elements of radiographic imaging. In orderto implement the virtualization of the radiographic imaging system. The realization of algorithm has beenstudied and the flow diagram of the software algorithm is represented. By adjust the parameter of thesoftware can realize different imaging results, at the end of the thesis the improving idea is proposed andthe virtual radiographic system designing based on Monte Carlo approach is also discussed, whichconstructed a foundation of future study in this area.