1. Engineering data holds the Ultimate Tensile Strength, but it has no effect on the solver. The solution will not stop when this value is reached. The only time this value is used is when you put the Stress Tool into the Results and plot the Factor of Safety. Then the UTS is divided by the Stress to compute the Factor of Safety. If the material model is a linear elastic material, the solution can take the stress result way past the UTS. It is only in Post Processing, that you can make a plot like the Factor of Safety to show if the material is over or under the failure value of UTS. I don't usually plot Factor of Safety. I prefer to just plot the stress (Max Principal for brittle materials, von Mises for ductile materials), and I set the value on the legend that separates orange from red at the value of UTS then any material colored red has failed. For ductile materials, instead of using a linear elastic material, I add a plasticity material model. That allows the material to stretch at values of stress above yield. Then instead of comparing stress to UTS, I look at Total Strain and compare that to Elongation. In this case, I set the threshold on the legend between orange and red to the value of Elongation and any material colored red has failed.
2. Solid65 is an element type not a material. Solid65 elements are designed to work with the Concrete material. When you use concrete and solid65 elements together, the material has failure mechanisms built in and the ability to simulate cracking and crushing. The problem with the concrete/solid65 combination is the results are extremely sensitive to the mesh used in the solution. You have to use very small elements and very slow loadings and a slightly different mesh can give a very different result.
Some people are more interested in the gradual failure of a concrete beam and a plasticity model is more useful than the cracking model used with Concrete/Solid65 approach. A plasticity model has been developed called Microplane that is very robust and gives accurate results across a wide range of meshes. You can read the Microplane example in the Technology Guide in 19.1. Here is a discussion on that topic.
3. You can put a plane at the center and use Slice, then put the two pieces in a Multibody part using Form New Part in DM.
4. You don't need any overhang, you can just apply the supports on the corner vertices.
5. Look on YouTube for tutorials on 2D design modeler.
6. In a 2D model without using symmetry about the center, you need one support to have X=0, Y=0 and the other support to have just Y=0. If you have symmetry at the center, then the one support only needs Y = 0 because the symmetry prevents motion in X.
7. You can apply a force to the entire top surface of a beam. That is called a distributed load. That is not how a 3-point bending test is done, but it is a valid load. Applying a displacement to the entire top surface is not a valid load. A typical 3-point bending test is to apply a displacement load to a point or small area at the center.