Official Answer
Answer
Hysteresis is the difference between the loading and unloading curves of a spring. In wave springs, this is primarily caused by friction between the spring and the bore (or rod) and internal friction in multi-turn/nested designs. The area inside the hysteresis loop represents energy dissipated as heat. While some damping is often desirable in mechanical systems to suppress vibrations, excessive hysteresis indicates binding or bore interference. If the hysteresis is non-linear or 'jerky,' it suggests stick-slip behavior, which can lead to fatigue failure. For precision applications, reducing the radial wall $b$ or improving the surface finish can minimize these effects.
