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Figure 3. von Mises equivalent stress distribution patterns for a representative Ti-6Al-7Nb model. The scale at the bottom describes the ranking of colors. The dark blue indicates the lowest stress values close to zero, and the red indicates the highest; areas in gray have stress values exceeding the proportional limit and therefore represent areas undergoing plastic deformation. A and C represent the stress distributions on loading for deflections that resulted in 25 µm and 350 µm permanent deformations, respectively, while B and D represent those on unloading. The inner upper corner and the opposing outer side, both showing the highest stress values, were especially projected. Each model was split at an 80-degree location to show the stress distribution inside the clasp. When unloaded, the residual stress patterns had a four-layer configuration: The 2 surface layers had stresses opposite those when loaded, while the deep 2 layers had the same stresses (blue arrows, compressive; red arrows, tensile). The inner upper corner showed the highest von Mises residual stress values (compressive). For clarity, different scales were used for the 4 Figs.
