Dear Shubham,

In all commercial software volume to volume contact or surface to surface elements are available..you can use those elements for simulating your problem..select the correct contact elements from element library and accordingly assign the material properties to the element. I suggest you to read ANSYS manual for further details in this regard..From the manual you have to look for contact elements..all the best..

Thanks Karthigeyan.

Can you tell me how will the increment time (computational time) (approx) vary if i go on creating a clump of spherical particles by overlapping spheres. Lets say i am using 5 spheres to create a clump eventually forming a non-spherical particle.

It is a very interested question ,I agree with Karthigeyan Answer

Dear Shubham,

The computational time depends on the problem..mean what is the kind of loading it undergo..you tell me, are you like to apply load after connecting all spherical elements..The interface properties need to be evaluated and assign them in the analysis. The interface properties mainly the normal and shear stiffness of the interface..the time required to complete the analysis is depending on the type of loading applied to the elements..All the best..