Discontinuous deformation analysis (DDA) simulation of celestial orbits

The numerical method of discontinuous deformation analysis (DDA) derived from the field of rock mechanics is used for the first time to simulate the motion of celestial systems. With celestial bodies being treated as rigid bodies, only the universal gravitation and inertial force of celestial bodies need to be considered in DDA simulations. Based on the variational principle of elastodynamics, linear equations describing the motion of celestial bodies were established and solved for obtaining the kinematic parameters at every time step. The plane rigid disk DDA method was used to simulate the motion of Sun-Earth system and Sun-Earth-Moon system respectively. The results were compared with those of astronomical software Stellarium, and the errors were small. The DDA method can be conveniently used to simulate the motion of celestial bodies.