The Ultra-light Artillery Structural Dynamics Finite Element Analysis And Overall Optimization Matching Technology Research

Towed howitzer is a complex structure system, its launching is a strong nonlinear, large-displacement dynamic process. The concept of system FEM modeling method for howitzer was established. Based on a large-calibre ultra weight-light towed howitzer, the soil bracing model was replaced by the mechanics model with lumped parameter, the launching dynamics FEM model of towed howitzer was established, which was reasonable simplified to reduce the size of the calculation in the premise of ensuring the accuracy. Then the whole howitzer's dynamical performance index such as recoil properties, firing stability, muzzle vibration and howitzer carriage's dynamic strength and stiffness in four firing conditions at the direction angle 0°and elevation angles 0°and 65°with two different charge. It could provide quantitative guides to the evaluation of design scheme of the howitzer, the design and improvement of howitzer carriage and functional component, and also provide a basis for the research on the part structure weight reduction and whole howitzer parameterized optimization.The elastic-plastic constitutive of soil is an important aspect affecting the dynamics in artillery firing. Based on the characteristics that towed artillery firing in the different ground, with Mohr-Coulomb yield criterion, a FEM dynamics model whose cradle Contacts with the ground was built at rigid bracing and close-qrained dense sand bracing, in order to analyse the effects under different ground reactions during artillery firing progress. Through the method depicted above, we could extremely cacluate the dynamical performance index with artillery firing on the soil, and prove the validity and practicability when replacing lumped parameter with close-qrained dense sand bracing.To ensure the firing stability is challenging in the design of ultra weight-light towed howitzers. Based on the whole structure of mainstream ultra weight-light towed howitzer, principles and approaches applicable to increase firing stability were studied. A design decision-making method to increase firing stability, based on Pareto multi-objective optimization theory, was put forward. Through constructing a towed howitzer's rigid-flexible coupling multi-body structural dynamic FEM parametric model and a multi-objective optimizing model including total mass and firing stability, this method can make tradeoff and multi-objective optimization matching over global parameters of towed howitzers. Through practically optimization computations and analysis, this paper reaches an overall parameter matching law and main design parameters of overall structure, which ensure the stability of this kind of towed howitzer. At last, a speed-time characteristic of hydraulic buffer device of back trail which is advantageous to the stability is proposed, which has been proved by simulation. The research depicted above will be of reference value to the design of ultra weight-light towed howitzers in China.