The Principal Normal Surface Of A Nonlightlike Curve In Minkowski 3-Space

In this paper,we study the properties of the principal normal surface of a nonlightlike curve in Minkowski-3 space.We define the Minkowski minimal locus.We study the singularities of the principal normal surface of a nonlightlike curve and we get some interesting results of the principal normal surface of Bertrand curves and Mannheim curves in Minkowski-3 space.