Continuum mechanics; nonlinear elasticity

Are there any papers/documents on one dimensional bar problem with a cohesive zone element formulation? It should be a zero length non-linear spring in this case right? I am more interested in setting up the problem from the virtual work principles rather than a discussion of the results.

Thanks

Hello, researchers. I have difficulty in understanding the physical meaning of Green-Lagrangian strain (E) and Eulerian-Almansi strain (A) measures. Mathematically speaking, I can derive the equations of these strains in different ways. But physically speaking, it's a bit harder to understand how these strains (E and A) can be pictured and how to give a proper physical definition for them. In a simple case, considering a uni-axial bar (Please refer the attached file), Engineering strain can be understood easily, but in E and A equations, from where do the squares of the lengths originate?

Dear iMechanica users,

I am working on a metallic foam model, and due to its nature of geometry and physical properties, I considered geometrical and physical nonlinearities. What is the significance of NLGEOM = ON and NLGEOM = OFF besides, it includes or excludes the geomterical nonlinearity in ABAQUS? I want to know the basic change that has been incorporated when I switch the NLGEOM between ON and OFF. Also, a theoretical explanation on how this change is caried out.