Local dimpling of the shell surface of a tank due to shrinkage effects

Metal silos and tanks are commonly constructed using isotropic curved plates to form unstiffened cylinders. Buckling failure under axial compression, which can be increased by local unsymmetrical normal pressures, is the controlling design consideration for most silos of this type. Tanks also may be susceptible to buckling under axial compression, for example as a result of uneven settlements beneath the shell wall (Holst & Rotter 2003, 2004). Often, however, the critical design parameter for cylindrical tanks is buckling under external pressure.