Integrated preparation method of three-dimensional auxetic structure of foam-filled composite material

The invention provides an integrated preparation method of a three-dimensional auxetic structure of a foam-filled composite material. The three-dimensional auxetic structure is integrally formed and manufactured by a vacuum assisted resin infusion (VARI) process; the structure consists of a plurality of unit bodies which have auxetic characteristics and are identical in structure; each unit body is of a three-dimensional double-arrow-shaped negative poisson's ratio structure and consists of an upper part and a lower part; and the upper part is laid by the fiber fabric as an arrow with a larger angle, and the lower part is laid by the fiber fabric as an arrow with a smaller angle. The invention breaks through a process flow that a traditional three-dimensional double-arrow negative poisson's ratio structure is made into a corrugated plate test piece by using a compression molding method, and then the corrugated plate test piece is subjected to interlocking molding after being cut by an engraving machine, and a