FATIGUE ANALYSIS OF A PRESSURE VESSEL WELDED JOINT USING THE STRESS INTEGRATION METHOD OUTLINED IN THE ASME BOILER PRESSURE VESSEL CODE VIII

摘要

A design challenge is to ensure the structural integrity of a pressure vessel to meet the regulatory requirements of the ASME Boiler & Pressure Vessel Code whilst minimizing material cost (wall thickness). The paper describes the fatigue analysis of a welded joint in a pressure vessel subjected to road transport loading. It describes the method used to recover the stresses that are critical for this fatigue analysis using the commercial software nCode DesignLife. Finite element analysis is used to calculate the structural stresses. The fatigue analysis uses detail stresses in the weld recovered using the stress integration method outlined in the ASME Boiler & Pressure Vessel Code VIII, Division 2. This method uses the structural stress at the location of interest, and the bending ratio associated with that stress. This avoids a specialized meshing scheme in the solid elements close to the weld.