Kittisak Kuntiyawichai and Suchart Limkatanyu

pp. 1289 - 1304

Abstract

       With the increase of the economic competition in the industrial world, much attention is being paid to the deterioration of the design structures before and after their first use. Even with the highest quality of materials and workmanship, the occurrence of some form of imperfections during manufacture is inevitable and there will be a typical distribution of imperfection sizes associated with a particular manufacturing process and quality. The origin of defects in a material can take place during manufacturing stage, or during
assembly, installation, commissioning or during in service. The defects will be generated due to deterioration of the component/structure which, in turn, results in deterioration of mechanical properties, crack initiation and propagation, leaks in pressurized components and catastrophic failures. Hence, Non Destructive Inspection (NDI) is required at regular intervals and the results can be used for maintenance to mitigate
fatigue risk. However, no in-service inspection is perfect. NDI outputs normally depend on many uncertain factors such as the condition of the inspected structure and its service environment etc. In order to take into account those uncertainties, the probabilistic approach is capable of identifying variables affecting the design
life of the components. It has also been proved that the probabilistic method can be extended to provide very useful information to help managers in making decisions regarding the operation and inspection time of the structures in order to maintain their reliability.
          In the present paper, a literature review of the current approaches and methodologies that has been utilized in the area of structural risk and reliability analysis for structures is presented. The parameters used to quantify the uncertainty and reliability of NDI technique is explored. Several probabilistic models regarding the updating flaw information and inspection schedule using different approaches are discussed. Finally,
examples of such application on engineering structures are presented.