17 April 2018
Sorry for the delay. You have a rectangular section, height x thickness and that section has some length. I put 3 elements, along the thickness direction.
Explain why you want to use no separation contact? I think it is because you want the beam to be free to "slide" or "roll" on that support. I achieved the same result by using a remote displacement, and only set the vertical DOF to be zero and left all the other DOFs Free, so I get that effect. I don't understand how no separation contact has anything to do with frp reinforcement, please clarify that.
One way to reduce the size of your model is to put a plane of symmetry at the center of the length, that will cut your model in half and allow you to use smaller elements on the remaining half without exceeding the student limit.
I don't know what you mean by "omission of shears", please explain that.
For your last question, I think creating a multi-step analysis will allow you to plot the crack at many intermediate loads to failure.