when i run a fatigue simulation, why are the materials all grayed out?  I have all my components defined in a fatigue study with standard and custom materials.  I do not have fatigue data for all the parts so ive been using the "derive from material elastic modulus-based on ASME austenitic steel curves" option.  I do have one part that i have the curve for.  However, all my parts are showing as one material.  The part i have selected should be SAC 305 and not VT-47