Hi DesertFox,
It's a funny one this. This is for a retractable spiral staircase that I am designing. The spring (in flat hoop form) is to be attached to the underside of a circular array of steps. As the steps move down relative to each other the spring is drawn radially inwards toward the stair...
I am trying to design a helical spring, using a glass fibre composite, of a single turn, that extends under load to such an extent that the outside diameter halves. All the assumptions of spring analysis (small deflections etc) no longer apply and I cannot work out any of the parameters relating...
