PEAK STRESS AND FATIGUE ASSESSMENT AT THE SADDLE SUPPORT OF A CYLINDRICAL VESSEL

The maximum stress in a saddle-supported cylindrical storage vessel is often the circumferential stress developed at the rips (or horns) of the saddle support. Although the peak stress at the support is not imm ediately detrimental to the integrity of a vessel, it would have a lon g-term effect on the fatigue life of the vessel. This article provides a parametric equation to determine the peak circumferential stress at the support. To assist calculations, a worksheet procedure has been p roposed. The parametric equation is accompanied by four graphs, each g raph provides values for a geometric variation of the problem. An exam ple has been shown on the application of the parametric equation. A fa tigue assessment is also made on the example vessel and comparison is made between ASME and British design codes. The parametric curves can be also used as a set of design curves for specifying support dimensio ns.