An experimental study has been made of the behaviour of "very thin" torispherical ends subjected to internal pressure. The seventeen ends tested were full-size production ends made from stainless steel, with thickness to diameter ratios (te/Di) varying from 0.002 to 0.001. At each value of te/Di the knuckle radius (ri) and crown radius (Ri) were varied to cover the range of ends frequently used. Each end was stain gauged on both inner and outer surfaces and then pressurised until buckling occurred in the knuckle region. The strain gauges were monitored throughout each test thus giving a detailed coverage of the strain distribution. High compressive hoop strains, shown to exist on both surfaces of the knuckle, are responsible for the buckling mode of failure. A shape/thickness survey was performed on each end prior to pressure testing. The effects of thickness reductions and deviations of curvature from the nominal are discussed. Residual strain measurements were made on three ends and were shown to be significantly large in the pressed and spun manufactured ends. A study of the effect of work hardening on the properties of the material from which the ends were made is also presented. It is shown that the proof stress and Vickers hardness number increases rapidly when the material is work hardened. The dependence of the elastic stress indices, limit pressures and first buckling pressures on wall thickness, knuckle radius and crown radius has been examined. The design implications of the study are discussed and a method for predicting the first buckling pressure of production ends given.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:450631 |
| Date | January 1975 |
| Creators | Campbell, T. D. |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://eprints.nottingham.ac.uk/13321/ |
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