Utilization ratio is delivered only when the member is designed by any specific steel design code. As there is no such explicit design rules available in the Design codes which designs any arbitrary plate elements, the design of these plate strips are not possible in Staad.
You can get the plate stress result like out of plate bending, out of plate shear or some interaction of stresses like Von-Mises, Principal Stress etc and you compare them with the allowable stress limit. Generally, depending on the type of structure, there are many failure criterion methods like maximum shear stress, Von misses, maximum stress theory , maximum strain theory etc are used to determine the failure criteria of steel elements
You can get the plate stress result like out of plate bending, out of plate shear or some interaction of stresses like Von-Mises, Principal Stress etc and you compare them with the allowable stress limit. Generally, depending on the type of structure, there are many failure criterion methods like maximum shear stress, Von misses, maximum stress theory , maximum strain theory etc are used to determine the failure criteria of steel elements