In FEMAP you can simulate a spring in different ways, CBUSH is one of this where you enter the stiffness of the spring using a value directly in the DOF you want, you can also use a CROD and play with values of A=Area, E=Young Module and L=Length to obtain the axial stiffness K= AE/L. Also you can use a CELAS2 spring element of NX NASTRAN using the element type in FEMAP named DOF SPRING, etc.. Here you are a tutorial in my SUPPORT website dealing with CROD & CELAS2 elements solved as linear SOL101 and nonlinear SOL106: http://www.iberisa.com/soporte/femap/nolineal/celas2_nolineal.htm
Please explain the problem you have more in detail, and then we will try to help you, OK?.
Best regards, Blas.
Blas Molero Hidalgo, Ingeniero Industrial, Director IBERISA • 48004 BILBAO (SPAIN) WEB: http://www.iberisa.com Blog Femap-NX Nastran: http://iberisa.wordpress.com/