The entered Safety Factor and with it the calculated Stress Goal from the material strength is the target of the optimisation. At the end of the optimisation all material should be evenly loaded with this value which always equals with a Failure Criterion value of 1.
The occurring stress highly depends on the applied loads. In most cases a Safety Factior Factor of 1 and with it the maximum strength of the material is not a suitable value. If the Stress Goal is assumed too high (Safety Factor too low) and the loads aren’t able to create stresses accordingly, all the material will be reduced.
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