Optimization Of Gun Firing Stability Based On Rigid - Flexible Coupling Dynamics

Firing stability is one of the key performance indices of artillery, which has important influence on firing accuracy, firing rate, and reliability. For purpose of improving stability of the howitzer, exploratory research is concerned for rigid and flexible coupling dynamics of launch process, and multi-objective optimization of firing stability for a large caliber gun by comprehensive utilization of artillery design theory, multi-body system dynamics, sensitivity analysis and optimization design theory, which can provide certain theoretical basis and technical reference for overall design and structure design of such artillery.First kind of Lagrange method based multi-body system dynamics equations are introduced. Component deformation mathematical method is described in light of modal expansion method. Calculation method of normal and tangential contact force in form of Dubosky is analyzed. Aiming at the detailed characteristics of differential equations of gun launch dynamics, numerical solution to rigid differential equations is emphatically discussed.Taking consideration of structure feature and characteristics of the launch process of a large caliber artillery, topological structure is given for artillery multi-body system. Finite element model of tube, cradle and upper carriage is established. Modal analysis is performed for obtaining natural vibration frequency and mode, nodes and elements information, which is used in computation of deformation for flexible components. Information exchange between flexible body, and rigid body, joint, load is realized through interface nodes. Mathematical model of launch loads is constructed, including bore force and forces generated by recoil mechanism, recuperator and equilibrator, and which is integrated into rigid and flexible coupling dynamics model by use of dynamic link library. Firing stability of the artillery is obtained by using the method of numerical calculation, and dynamic stability during recoil and counter recoil period is analyzed. The established dynamics model is verified by using the measured results from firing experiment.Sensitivity analysis model is constructed for overall structure parameters. Based on rigid and flexible coupling dynamics model, and objective functions including firing stability and muzzle disturbance, experiment design is investigated, and the overall structure parameters which take great influence on firing stability and muzzle disturbance are selected, which will provide foundation for optimization.Design variables, constraints and objective functions are defined. According to data structure of ADAMS/Solver model, genetic algorithm based Fortran language codes are developed for multi-objective optimization of firing stability and muzzle disturbance. A couple of optimizations are performed for overall structure parameters of a large caliber gun. The optimized structural parameters are rounded, and then rigid and flexible coupling dynamics computation is examined, and finally the conclusion that the effect of firing stability and muzzle disturbance optimization is notable is drawn.