In order to model masonry infill as strut, you can follow the FEMA 273 method of pin jointed struts. You also need to define the nonlinear behaviour of the infill materials. (Show Advanced Properties -> Nonlinear) - Stress-strain curve needs to be put in.

Next you go to Define-> Section Properties-> Hinge Properties-> Input the hinge properties

You also need to keep in mind the for the strut elements, tension limit in set to zero and mass is zero, because you will incorporate the infill as equivalent distributed load on the beams.

Please, check the following two papers. Sorry, they are written in Spanish. 

Article Influencia de la mampostería no reforzada en el comportamien...

Article Modelación inelástica de pórticos de concreto con mamposterí...

For the masonry infill wall use the cross braces with moment released mean pinned joint connection with the width equal to the width or the masonry wall and depth equal to 0.25 times length of diagonal length. 

In order to model masonry infill as strut, you can follow the FEMA 273 method of pin jointed struts. You also need to define the nonlinear behaviour of the infill materials. (Show Advanced Properties -> Nonlinear) - Stress-strain curve needs to be put in.

Next you go to Define-> Section Properties-> Hinge Properties-> Input the hinge properties

You also need to keep in mind the for the strut elements, tension limit in set to zero and mass is zero, because you will incorporate the infill as equivalent distributed load on the beams.

1. I am finding difficulties for material selection in case of masonry.

2. For strut, what will be the element type? Do I need to consider cross bracing as a Beam?

Thank you everyone. Could anyone please provide me such example file in sap 2000?

for selecting the materials for masonry you have to define new material as there is no material is define in sap library for masonry 

for this purpose select Define Materials > Add new material > and in material type select other and then provide the unit weight modulus of elasticity of masonry and other properties

What type of section properties should I select for bracing?

e.g for providing brick masonry use 120 lbs/ft^3 unit weight, Poisson ratio of brick, modulus of elasticity E of brick and coefficient of thermal expansion A of brick and then press OK for creating new material 

I create the material type, but my question is..."which type of section do I need when I shall incorporate bracing?" Do I need to make frame/ tendon or link? which section type should I choose?

use frame section but pinned joint moment released 

thanks Tufail, could you please tell me how can I calculate the values for strength envelope (like Madan et al).

Mr. Ritukesh Bharali, Can you give an example to calculate stress-strain curve for sap input?

You'll find the curve in this paper along with the expected pushover plots. However, the material properties for your country might be different.

Hope this helps. Goodluck

An important parameter is infills not to carry any gravity loads. Does SAP takes this into account?   

Mr. Anastasios Andreadakis, the masonry action will be represented by a strut, which means it will take only compressive axial loading. The member will not take any shear or moment. There is an option in SAP under "Assign" -> "Partial Fixity" where you can release them.

I don't mean that, i mean that struts should not carry any axial load caused by gravity loading (that's why they are called "infills") but they should be activated only when they are subjected to lateral (seismic) forces.

Only -compression struts can be used only in nonlinear analysis. In linear seismic analysis you should use some of simplified techniques and prevent that infills bears gravity loads.

After creating frames..how can I provide infill walls in that?

Can any one give correct procedure for that?I want to provide openings in it.how can I provide that?

if your wall have opening i-e windows and doors then your stiffness and strength of compression strut will be reduced by a formula .you can find in any of the paper related to the modelling of the infill wall 

Please see the discussion here:

http://www.sepakistan.com/topic/1343-seismic-assessment-and-retrofit-design/

Thanks.

I agree with Ritukesh Bharali.

Dear Ram..this link may be beneficial for you

www.iitk.ac.in/nicee/wcee/article/2060.pdf

thank you

Generally in bare frame behavior, gravity loads are transferred form slab to the beams and than to the column at the joints. So to avoid the gravity load transfer in infill panels,pin connections at the end of equivalent strut should not be connected to the beam column joint.It should be connected to the column only at some distance below from the face of the column.....for more detail please go through the attached pdf..may be helpful.

Dear Ram. I recommend you the two following papers. Best regards.

Article Modelación inelástica de pórticos de concreto con mamposterí...

Article Influencia de la mampostería no reforzada en el comportamien...