Elastic analysis of semi-elliptical axial cracks in cylinders under thermal shock using BS 7910 framework

One of the most common and important situations involving flaws in pressure vessels is the internal thermal shock of a hollow circular cylinder with an axial semi-elliptical internal surface crack. The current approaches available to analyse this specific problem are excessively conservative or cumbersome. This paper considers the internal thermal shock problem and determines the stress-intensity factors for shallowest and deepest points for cylinders with the ratio of thickness to inner radius 0.1 and 0.25. The results of calculations are presented in a similar form to the draft standard BS 7910:1997 and thus permit numerous practical applications. These results are in many cases much less conservative than the draft standard and also reveal some important cases.