Dynamic model for internally carried air-launched rocket

Abstract

For rigid-flexible coupling multi-body with variable topology, such as the system of internally carried air-launched or heavy cargo airdrop, in order to construct a dynamic model with unified form, avoid redundancy in the modeling process and make the solution independent, a method based on the equivalent rigidization model was proposed. It divides a system into independent subsystems by cutting off the joints, of which types are changed with the operation process of the system. And models of different subsystems can be constructed via selecting suitable modeling methods. Subsystem models with flexible bodies are on the basis of the equivalent rigidization model which replaces the flexible bodies with the virtual rigid bodies. And the solution for sanction, which is based on the constraints force algorithm (CFA) and vector mechanics, can be independent on the state equations. The internally carried air-launched system was taken as an example for verifying validity and feasibility of the method and theory. The dynamic model of aircraft-rocket-parachute system in the entire phase was constructed. Comparing the modeling method with the others, the modeling process was programmed; and form of the model is unified and simple. The model, method and theory can be used to analyze other similar systems such as heavy cargo airdrop system and capsule parachute recovery system.

摘要

针对类似于内装式空中发射多体系统及重装空投系统的变拓扑结构刚-柔耦合多体系统, 为建 立形式统一的动力学模型, 并避免单一建模方法的冗余建模过程, 提出基于等效刚化的建模方法。在 建模过程中, 截断在系统工作过程中拓扑结构发生变化的铰。包含柔性体的子系统采用等效刚化的建 模方法, 其他子系统可根据需要选择合适的建模方法。在计算过程中, 根据约束力计算算法及矢量力 学理论可将约束力与状态方程独立求解。以内装式空中发射系统的动力学模型建立为例子, 验证了基 于等效刚化的建模方法的有效性和正确性, 并分阶段建立了空中发射系统的动力学模型。与其他建模 方法相比, 上述理论得到的动力学模型在不同阶段具有统一的形式, 建模过程简单且程序化。等效刚 化的建模方法及其相关理论可应用于类似的刚-柔耦合多体系统。