Sean Harvey
Ansys Employee

Hello Henrique,

Have you see our partner Cornell course on this classic problem?  

Hertz Contact Mechanics - ANSYS Innovation Courses

What might be happening in your case is to check if the two bodies are in initial contact with no gap. You should use auto time stepping and specify initial, min and max substeps as you could be loading too quickly.

BTW, the topic of loading parts that are close but not touching is covered in this great lesson.

How To Utilize Contact Stabilization Damping Correctly — Lesson 2 - ANSYS Innovation Courses

Please try and let us know.