The ornamental design of flat deck structure having curved elements, as shown and described above.
FIG. 1 is a perspective plan view of the flat deck structure having curved elements of the new design. Detail of the opposite side of the flat deck structure having curved elements shown in FIG. 1 is easily deduced from the view shown in FIG. 1, and all detail is evident from FIG. 1.
FIG. 2 is a side elevation view of the flat deck structure having curved elements of FIG. 1; and,
FIG. 3 is an end elevation view of the flat deck structure having curved elements of FIGS. 1 and 2.