I'm user of Sap2000nonlinear for a long time and i must admit i as suprised by your question.Personally i don't think it's possible to do that.You can assign initial disp easily but not initial accel or vel.Sorry
I'd recommend Anil Chopra(dynamics of Structures).In chapter 20 refers to base isolation and has several examples.Also you can find very useful articles in ASCE about base isolation and base isolation retrofit.
About software SAP2000 nonlinear has extended capabilities on base isolation but i'd...
i agree with the above answer.You must be very careful allthough when giving properties in the hook element.You'll find a very good example of a structure with hook element in www.csiberkeley.com in sap2000 training problems
I could really use your help on a matter conserning SAP2000.What i'm trying to do is study a steel frame and its plastic mechanism.I'm having real problems with the nonlinear dynamic analysis.How can we assign the plastic1 element in SAP2000? Should we add joints close to the given ones and draw...