>>>> Winniw Leung wrote: Leong Cheng Chit also has quite a few curved > tension models on his flickr site. In fact he's come up with some sort > of categorisation for the different folds. > http://www.flickr.com/photos/chengchit/920470628/in/photostream
That was an early attempt of mine to categorise the folds for curved surfaces. The mathematician Gauss has categorised three fundamental curved surfaces - cylinder/cone, dome and saddle. The first is developable and the other two are not. I use a couplet or flange with a single cusp to simulate the dome and a couplet with double cusps to simulate the saddle. I avoid using the term "tension". This is because there will always be tension in the paper when you bend or fold it. Even a flat folded model would open into a 3D form, unless there are folds to lock it. The single and double cusp couplet folds are stable (in practice, relatively more stable). Cheng Chit
