How does axial misalignment of mating surfaces affect the fatigue life of a Crest-to-Crest wave spring?

If the mating surfaces (e.g., a bearing race and a housing shoulder) are not parallel, the wave spring is subjected to non-uniform loading. One side of the spring will undergo higher deflection than the other. This creates a sinusoidal stress distribution around the circumference of the spring. The maximum stress $\sigma_{max}$ will occur at the crest of the most compressed wave, leading to localized fatigue cracking. Engineers should ensure parallelism within $0.002$ inches per inch of diameter to maintain the calculated $L_{10}$ life of the assembly.