Research On Launch Dynamics And Lateral Stability Of A Vehicular Dual-launch Platform

The intermediate and long-range missiles are crucial to the strategic strike purpose in the war.Therefore,the realization of the vehicular dual-launch platform has profound significance to the intermediate and long-range missiles for enhancing their mobile ability and combat effectiveness.This thesis takes a vehicular dual-launch platform of the intermediate and longrange missiles as the research object and conducts an in-depth research on the road-mobile launch dynamic issues including launch dynamics,effect factors,and lateral stability,which provides a theoretical reference for the system design and optimization of the vehicular duallaunch platform.The contribution of the paper is summarized as follows.1.The theory of multi-rigid-body dynamics and the finite element dynamic method are presented.The numerical solution methods of the system dynamic equations are introduced.It lays a solid theoretical foundation for the modelling and analysis of the vehicular duallaunch platform.2.An overall layout scheme for the vehicular dual-launch platform is proposed and a finite element model of the vehicular dual-launch platform is established in consideration of the surface-to-surface interaction.By the CFD method and dynamic mesh technique,the gas flow field and the emission impact load of three different structure deflectors are obtained.A comparative analysis of the results of the multi-rigid-body model,the rigid-flexible coupling model,and the finite element model is conducted and the accuracy and the applicability for the vehicular dual-launch platform of each model are concluded.Based on the finite element model,implicit dynamics method is employed to analyze the difference of the launch dynamic response between the two missiles.And the missile initial accuracy,the launch platform stability,and the overload of the second missile under the influence of three different deflectors are studied.The results show that the vehicular dual-launch platform equipped with the U-type deflector outperforms and shows practical application prospect.3.Based on the nonlinear finite element numerical calculation,the influences of engine thrust misalignment angle,ground inclination angle,ground friction coefficient,and rail friction coefficient on the launch accuracy and the platform stability are summarized,which has important meaning for screening launch environment and enhancing launch safety.A finite element model with initial ground stress is built based on the semi-rigid asphalt pavement launch site characteristics.The launch site sedimentation influence of different soil foundation elastic modulus on the launch process is analyzed,which provides data support for the mobile launch site selection.4.Considering the structural and mechanical characteristics of the hydro-pneumatic suspension,the steering strategy,the suitable tire model,and the flexibility of the chassis and the launch frame,the rigid-flexible coupling dynamic model of the vehicle dual-launch platform is established.By applying the Hankel transform and the inverse Fourier method,an isotropic three-dimensional stochastic excitation road model is generated.The road model has shown a high consistency with the ideal power spectral density,which means it is qualified for the driving simulation.A full-size vehicle test has been carried out to validate the model.The influences of different levels of road roughness on the lateral stability of the launch platform are analyzed.The safe cornering speeds for different missile-carrying status are given,which could effectively improve the mobile safety of the vehicular dual-launch platform.