See also the Contact Accuracy section for more information about buffer range.
The solver assumes that all geometries inside the buffer range will soon be in contact. The buffer range is determined by the Buffer Range Factor such that:
Buffer Range = Max. Penetration · Buffer Range Factor
Contact search efficiency will be reduced if too large a value is used and solving time will also be increased. Too small a value may cause an inaccurate solution to the problem. You should use a value of 1/10 to 1/5 of the radius of curvature.