G0301003 Optimization of Threaded Cover Structure of the Pressure Vessel : Consideration of the Thread Modeling for FEA

Abstract

Stress concentration occurs in the root of threads in the threaded cover structure of the pressure vessel. The internal pressure causes unequal load distribution of threads and stress concentration in the root of threads. Then, it is necessary to consider the fatigue fracture because of the stress concentration. In previous study, the improvement of the load distribution and unequal stress distribution in the threaded portion of the pressure vessel is considered by using a FEA. In this study, it was carried out hydraulic test to the threaded cover structure of the pressure vessel. Then, it was put strain gauges on the outer surface of the pressure vessel in order to measure axial strain. On the other hand, making a model of the pressure vessel of hydraulic test using Abaqus. Results of the FEA shows that setting of the tolerance of thread and the coefficient of friction affect the analysis results. Therefore, it shows the effect on the analysis result by the setting of tolerance of thread and the coefficient of friction. And, it shows a comparison with the strain obtained from the strain measurement results of the hydraulic test and analysis results.