A Full 3D Finite Element Model for Buckling Analysis of Stiffened Steel Liners in Hydroelectric Pressure Tunnels

Abstract

The availability of tools for safety evaluation of a pressure liner is a relevant issue in both

A Comparative Review of the Current Methods of Analysis and Design of Stiffened and Unstiffened Steel Liners

“…In this case, the material is not used to the full. Regardless, geometric nonlinearity should be considered in the model [17].…”

“…Earlier work included a comparison of some analytical methods, such as those of Donnell, Roark and von Mises [17]. The applied data set for that comparison is shown in Table 5.…”

“…It should be noted that whereas the formulations offered by Amstutz, Jacobsen, and Montel are applicable when failure is produced by yielding [17], the remainder consider only failure due to geometric instability, which is uncommon for D/t ratios of between 100 and 300. One simple manner for comparing such formulations involves determining the factor K, which depends on the material of the liner, geometry, and size of the gap [33,34].…”

“…In another case study [17], for a gap of 0.6 mm, the results obtained by different methods were compared with those achieved through a finite element model. Figure 12 shows that the latter follow the values obtained by Montel and Jacobsen.…”

“…The parameters that define the slenderness of a stiffened liner are D/t and L/D (spacing of stiffeners). Since the most commonly used method is that of Jacobsen [19], its results were compared with those from three-dimensional finite element models [17]. El Sawy [21,27] compared the values obtained for unstiffened liners with the Jacobsen formulation, showing that the latter is conservative for usual D/t values; however this would not be so for thin-walled liners.…”