Can anyone tell me how to specify a skid steel structure completely resting on a concrete slab as mentioned in below picture.
how to specify the support type for the steel skid.?
I won't analyze this skid in this way because obviously all elements will pass the design. Use lifting analysis instead. Locate your padeyes and support them by slings.
Can you tell, Is there any tool in STAAD to design padeye or slings?
For padeye, model it separately as FE then apply the forces and check the stress limits. For sling, obviously it is a tension member, just take the the internal tension force from the staad model and compare it with its capacity.Capacity should be greater than the actual force. You can use the simple stress formula with reduction factor when calculating tensile capacity.