Hi, I often need to draw a bellows-shaped wave along a curvilinear path (this path is a belt).

The behavior of the bellows-shaped continuous wave is that it remains constant in the straight sections of the path, while in the curves changes shape in the following way:

when the curve "open", the crest of the bellows extends and expands,

when the curve "close", the ridge narrows and compresses the bellows,

Instead the base, the bellows is essentially unchanged.

I have tried in various ways to draw the bellows in a realistic way, but the best of my results is not satisfactory

Could you help me? How can be designed this bellows (with Swx2012)?

... bad

straight sections

curve "open"

curve "close"