Improved systems and methods of creating a smooth contact-impact interface (i.e., a curve fitted surface) in finite element analysis are disclosed. According to one aspect, a smooth contact interface is created for a master segment used for simulating contacts. First, for every nodal point in the master segment, a list of elements that share at least the node is determined. Then a nodal normal vector is calculated using a weighted average of respective element normal vectors of all elements in the list. The calculated nodal normal vector is adjusted for special edge effect, which is an intersection between flat and curved geometries. A set of edge control points are created using a pair of adjacent corner nodes. A mid-element control point is further created for quadrilateral shell elements. The smooth contact interface is configured to encompass all corner nodes and all of the control points.