Dynamic modeling method for large-deformation blade structure

The invention belongs to the field of helicopter rotor design, and relates to a modeling method for a large-deformation blade structure. A paddle is divided into a plurality of straight beam sections, a floating coordinate system is established at the left end point of each paddle straight beam section, and large-range rigid body motion and any-angle rotation of the paddle straight beam sections are respectively described through three translational degrees of freedom and three rotational degrees of freedom of the floating coordinate system; the elastic deformation of the straight beam section of the blade is described relative to a floating coordinate system, and connection deformation coordination is performed through a cantilever type butt joint constraint equation, so that the large-deformation motion of the blade beam structure is decomposed into large-range rigid body motion of the floating coordinate system or superposition of medium and small elastic deformation relative to the floating coordinate sys