THE DEVELOPMENT AND APPLICATION OF NUMERICAL PLATFORM FOR THREADED CONNECTIONS UNDER COMPLEX LOADS

With the exploration of oil and gas sources moves further to greater depths and into harsher environments, the working condition of pipe string becomes increasingly severe. As the weakest part of the string, the failure of threaded connections occurs frequently. Full-scale experiments are costly, time consuming and complex loads are difficult to apply. Based on three-dimensional elasto-plastic finite element analysis, a numerical platform for threaded connections is developed, which is a powerful complement to physical experiments. The calculated ultimate working torque of threaded connections by the numerical platform is consistent with the data in API standard (without axial tension). Furthermore, the numerical platform can be used to analyze the three-dimensional mechanical properties of threaded connections under complex loads. The numerical platform can evaluate the structural and sealing integrity of threaded connections accurately, and determine the load limits of threaded connections.