基于灵敏度分析的机枪结构动力修改研究

Structural Dynamical Modification Research of Machine Gun Based on Sensitivity Analysis

介绍了机械结构灵敏度分析的基本理论,探讨了用有限元法进行结构优化和灵敏度分析的一般过程.以某型机枪的枪架为例建立了有限元结构分析模型,选择枪架的弯曲刚度、扭转刚度和整枪的第一阶固有频率为性能约束,根据灵敏度分析结果,按高强度、轻质量的要求,选择出有效的设计变量进行了重量最轻和性能最优的结构优化.同时,利用试验测试数据对优化前后武器的动态响应进行了仿真对比,结果表明,优化后武器的射击频率与固有频率的匹配更加合理,提高了武器的射击精度.

The basic theories about structural sensitivity analysis are introduced, and the general method of structural optimization and sensitivity analysis based on the finite element method are presented. The finite element structural analysis model is established for a certain machine gun. The bending stiffness, torsion stiffness and the first inherent frequency are selected to form the performance restraints. According to the results of the sensitivity analysis and the demand of high stiffness and light mass, the effective design variables are chosen to optimize the mass and performance of structure, and these dynamical responses of weapon were simulated and contrasted between before and after the optimization by experimental testing results, which show that the matching between inherence vibration frequency and fire frequency becomes better, and the firing accuracy of a machine gun is improved.