You can use FEMA-356 chapter 7 section 7.5 for linear and nonlinear modelling of infill walls.

You can use the nonlinear link element in SAP2000 to model the strut action of the infill panel which acts as a bracing element (pin connected to the bounding frame). The effective width for the strut element can be computed according to the model you intend to adopt. You can, for example, use the model adopted by FEMA 356.

You can use the multilinear plastic link in ETABS or SAP 2000 to model the strut action of the infill panel. 

I think that ASCE41 strut is very stiffness, so, I think it's better to use the expression of Mainstone(1974) or similar. 

how to model multilinear plastic link?? Please give some idea @cristiano otto Bay

Following