Reply To: Please help. Very important for me

[danielshaw]

It is impossible to say without knowing more details about the model.  However, the stress reported in the stainless steel model is much less than the stress in the titanium model, so it is not surprising that the safety factor and predicted life are larger.  You need to compare the properties (particularly E and CTE) for each material to assess wihy stainless produces less stress than the titanium.