How can we implement Brazilian split tensile test?

Hi, I am trying to code Brazilian split tensile do anyone have the reference code. As I’m facing issue. Phase field value gets very small increment.
The code I did was simply took 1mm x 1mm square domain code for tensile test. In that I had applied - t for compressive force and the domain is circular domain(150 mm radius) with small 20 mm flat at top and bottom to apply boundary condition.