Cylindrical shells, buckling under

Use of rib stiffening was required. It was found necessary to stiffen the cylindrical shell against buckling under external pressure from ground water and dimpling from local earth pressure due to surface wheel loads. Sandwich wall construction was investigated as an alternative to use of stiffening ribs and found to be feasible but less cost effective. 

Most cylindrical shells are subjected to various compressive forces such as dead weight, wind loads, earthquakes, and vacuum. The behavior of cylindrical shells under these compressive forces is different from those under internal pressure. In most instances, the difference is due to the buckling phenomena that render cylindrical shells weaker in compression than in tension,... 

P. P. Bijlaard, "Buckling under external pressure of cylindrical shells evenly stiffened by rings only," J. Aeronaut. Sci., (June, 1957). 

Schneider W, Biede A (2005) Consistent equivalent geometric imperfections for the numerical buckling strength verification of cylindrical shells under uniform external pressure. Thin-Walled Struct 43(2) 175-188 Schneider W, Timmel I, Hdhn K (2005) The conception of quasi-collapse-affine imperfections a new approach to unfavourable imperfections of thin-walled shell stmc-tures. Thin-Walled Struct 43(8) 1202-1224 Stricklin JA, Haisler WE, von Riesemann WA (1973) Evaluation of solution procedures for material and/or geometrically nonlinear structural analysis. AIAAJll(3) 292-299... 

A review article gives a thorough review of creep instability of steel and other metal shells and pressure vessels at elevated temperatures. Some of the same analyses can be adopted here for polymers at lower temperatures, for example, room temperature. For example, consider the axisymmetric buckling mode of a cylindrical shell under compression. (The beam column mode can be included under column buckling. Section 4.2.) For the axisymmetric mode, where axisymmetric buckling waves occur for RJh < 33, the critical buckling stress in compression is given by... 

Find the critical time and the critical strain for creep buckling for an axisymmetric mode of a cylindrical shell under compression for 0, = 1600 psi, where h = 0.1 in., R = 3.0 in., v = 0.4. The solution involves an iterative method. 

Figure 6.21 shows the fabrication of the active surface structures reported by Holmes [17] using the Euler buckling of plates to generate a controlled array of microlens shells under equibiaxial compressive stress. First, cylindrical posts of photoresist (PR) were photopatterned onto a silicon wafer, followed by micromolding a PDMS elastomer onto the silicon substrate, creating an array of holes. This elastic PDMS elastomer film with an array of holes then underwent equibiaxial strain through an inflation procedure. 

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