In this paper, simplified finite element analysis is used to predict the occurrence of ratcheting for piping system subjected to constant internal pressure and dynamic load. The simplified FE analysis requires two FE analysis, elastic analysis and elastic-perfectly plastic analysis. The shakedown limit load of elbow included in piping system is calculated using the simplified FE analysis. Then the ratcheting occurrence is estimated by comparing the bending moment acting on the piping system calculated by FE analysis with the shakedown limit load.