Abstract

The presence of mechanically formed corrugations in thin metallic shells has been shown to have a dramatic effect on mechanical behaviour, such as creating orthotropy in isotropic shells. This offers the potential to tailor the mechanics of shell structures for a particular application, thereby increasing efficiency. For analysis purposes, it is common to treat the crease line as a singular rotational hinge, often combined with a torsional spring to provide elastic resistance to opening. We examine this assumption for creases in thin metallic strips by endowing the crease with a finite, but small, geometry and approaching the singular limit. We show that when the crease dimensions are on the order of the shell thickness, stretching along the crease line must occur. A simple model is developed incorporating this stretching, which allows a good prediction of experimentally observed flexural behaviour.