Limit Load Analysis Of Creep Damaged Pipes Containing Volume Defects

After long-time service under high temperature, creep damage will be induced in piping components. At the same time, volume defects, such as pits and local thinning, can be generated due to corrosion and/or erosion. All these factors will reduce the load carrying capacity of the structure. Therefore, limit load analysis of creep damaged piping components containing volume defects is of great significance to ensure the safety of pressurized piping components.High temperature tensile tests and creep tests were carried out to determine the mechanical parameters of the creep damaged material. Finite element program ABAQUS was used to analyze the limit load of the high-temperature damaged pipes containing volumetric defects. The main research work and conclusions are summarized as follows:(1) High temperature tensile tests creep test on2.25CrlMo were carried out. Elastic-plastic response model of creep damaged materials was derived. The model was verified by the available literature data;(2) Based on the elastic-plastic response model, finite element simulation was carried out to analyze limit load of pipes containing pits in long-time service. Limit load prediction equation of creep damaged pipes with pits under high temperature was obtained by fitting the FEM results. The predicted results from the limit load equation of the structure was compared with the existing formula;(3) The limit load of creep damaged pipes containing local thinning was also studied. Limit load equation of creep damaged pipes with local thinning was derived. The obtained equations provide the basis for limit load and reliability analysis of high temperature pipeline containing volume defects.