Full Description

Pressure vessel strength analysis procedures, such as the rules embodied in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, were evolved from practical experience until the mid-1940's. The experience was, for the most part, with low strength carbon steels. Fatigue failures were relatively rare because most pressure vessel services did not involve significant fatigue loading, and the low membrane stress levels and high ductility of the materials used helped to compensate for stress concentrations at local geometric discontinuities. The availability of economical higher strength steels, with much higher ratios of yield to ultimate strengths than carbon steels, with new demands on pressure vessel strength required review and revision of design and fabrication procedures to permit efficient and safe design. The information required to establish new design criteria have been developed by controlled experiments rather than from service experience. Low cycle fatigue strength is one of the several design factors, selected by ASME as requiring investigation, which the Pressure Vessel Research Committee (PVRC) undertook to study. This paper is a report of the data and information gained from a study of the low-cycle fatigue strength of pressure vessels fabricated by good commercial practice as opposed to the usual laboratory specimen which is machined to close tolerances. The vessels tested were cylindrical shells, 7ft. long, with a 36-in. ID, a 2-in. wall and hemispherical end closures, one with a 1-in. wall. The vessels contained from six to eight reinforced openings which are described in detail in this paper. The test conditions were established to study the relationships between specific variables and not to simulate service behavior. The results of these vessel tests must be related to predictions of service life through these relationships and must not be considered to be typical of pressure vessel service.

Product Details

Published: 1968 Number of Pages: 54 File Size: 1 file , 3.2 MB