Abstract: Based on Lagrange mechanics and starting from analytical mechanics, a fivedegree-of-freedom dynamic model of the terminal descent of a parachuteprojectile system is developed. Compared with the parachute system models based on Newton mechanics, this model is better for multibody dynamics, for the solution of binding forces between the parachute and the projectile is avoided. The Lagrange mechanics modeling process is introduced in detail. The parachuteprojectile system’s kinetic energy equation is deduced and the generalized forces are solved. Through an example, the validity of the model is verified by comparing the parachuteprojectile dynamic models based on Lagrange mechanics and Newton mechanics. The feasibility of the flight vehicle dynamic modeling process based on Lagrange mechanics is verified, which provides theoretical basis of using ADAMS to solve the parachuteprojectile system dynamics problems. This method can be used in the parachute-projectile system analysis and design.

Key words: parachutes, multi-body dynamics, Lagrange mechanics, flight dynamics, exterior ballistics