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In this case two iterations on the last Resolution Level are entered. How to adjust the number of iterations for each Resolution Level is explained here.
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The optimisation starts with the modified geometry as the first iteration. At the end of the optimisation the strut is integrated completely into the design. Because the new strut is now loaded with stresses other areas of the geometry are less loaded. The optimisation reduces the material accordingly at these areas, thus in most cases the new, modified design is as lightweight as the previous one.
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