About this 3D model
The outer radius is about 2.95 in (75 mm). The average bangle bracelet size is between 2.3-2.5 in. I left room for you to make some minor sizing adjustments. This was a relatively quick design. I made a twisted torus first. I scaled the torus up and applied a mosaic pattern. I then inset by polygon and deleted the faces leaving a frame. I shelled it and applied a turbo-smooth to create the voronoi appearance. It took me about 30 minutes of trial and error before settling on this design. Rendering the three pictures took about an hour.