Modal Method for Dynamics Analysis of Cantilever Type Structures at Large Rotational Deformations

The modal warping method is extended to a floating frame of reference formulation to combine modal warping formula with rigid body simulation. The highly nonlinear mass matrix because of the inertia coupling between the reference and the elastic displacements is approximated using the linear theory of elastodynamics. By kinematics analysis of infinitesimal deformation, the calculation of rotation deformations is derived. Then modal warping method is used to model deformations for numerical accuracy and computation efficiency. The rigid-flex multibody model for a leaf spring landing gear system is developed. The accuracy of the proposed method is examined by experimental/simulation comparison.