Official Answer
Answer
Nested wave springs consist of multiple turns wound in parallel. The total load $P_{total}$ is the product of the number of turns $n$ and the load of a single turn $P_s$, such that $P_{total} = n \times \frac{E b t^3 N f K}{D_m^3}$. However, friction between the layers must be accounted for, typically introducing a hysteresis loop in the load-deflection curve. The thickness $t$ in the stress equation $\sigma = \frac{3 \pi P D_m}{2 N^2 b t^2}$ refers to the individual layer thickness. This configuration is ideal for applications like heavy-duty valve seals where space is restricted but $P$ must be very high ($> 5000$ N).
