Karpash M. Development of methods, means and technologies for multi-parameter technical state evaluation of main pipelines

Results of modern state and trends of development of national and foreign achievements in the research topic are provided what acted as grounding for further research task formulation. Methodology for metallic structures' technical state assessment, including main pipelines, using multiparameter methods was proposed, which focuses on application of novel genetic methods for selection and non-linear optimization of informative parameters related with inspected object quality and can be measured using available technical means - this became a theoretical basis for development of new means and technologies of technical state assessment using different methods. The character and types of relationships between mechanical properties and microstructure of steel pipelines was established. Also complex sets of informative parameters for yield strength and fracture toughness evaluation were selected and investigated, which allowed to raise reliability of mechanical properties evaluation. New methods for control of parameters, responsible for metallic structures technical state were proposed and experimentally verified. Firstly, sensitivity enhancement method has been proposed for ultrasonic testing of materials, which allows reliable detection of different defects under noisy conditions. Secondly, method of defect classification was proposed which allow to distinguish between flaws of manufacturing and operating origin. Thirdly, non-destructive methods for yield strength and fracture toughness of steel structures were proposed and investigated.