How to apply boundary conditions for a chain of bonded particles

Hello Everyone,

I have bonded a string of particles together using Rotational bonds and made a chain.
I think the following paper contains the theory:
Wang, Y.C. (2009) "A new algorithm to model the dynamics of 3-D bonded rigid bodies with rotations", Acta Geotechnica, 4(2), 117-127.
In this paper, the authors have also showed some deformation results (Fig. 5) by applying boundary conditions of compressing, shearing, pure bending, pure twisting and bending plus twisting loading to the bonded chain.

I want some suggestion on how I can apply such boundary conditions to my bonded chain of particles. I want to apply atleast tensile or compressive loading to the bonded chain of particles. For the tensile loading Can I apply forces to the end particles of the bonded chain?

I will be really glad to get some suggestions. Thanks.