Study On Nonlinear Characteristics Of A Self-Propelled Gun Seat Suspension

Self-propelled artillery can cause severe low-frequency vibration of the whole body due to the complicated working environment,poor road conditions,and vibration of the vehicle power transmission system.This kind of vibration leads to various occupational diseases and causes physical and psychological harm to the driver,which affects not only the combat capability but also the related The treatment of occupational diseases also increases social costs.The self-propelled artillery seat is a key part of the vibration transmission path to the driver,and is in direct contact with the driver over a large area.The seat suspension plays a decisive role in the vibration isolation performance of the seat.This paper studies the static characteristics of a self-propelled artillery seat nonlinear suspension,establishes a 8DOF self-propelled artillery seat-human dynamics model,studies the dynamic characteristics of a self-propelled artillery seat-human system,and innovatively designs a rotary-rod mechanism.Seat suspension nonlinear.The main work of the dissertation is as follows:(1)Study on Static Characteristics of Seat Nonlinear Suspension System.Based on the principle of conservation of energy,a mathematical model of the static characteristics of a self-propelled artillery seat's nonlinear suspension was established.Simulations were performed using ADAMS software.Based on this,the influence of various design parameters on the static characteristics of the seat's nonlinear suspension was analyzed.In addition,by analyzing the typical linear vibration isolation transmission curves and formulas,the basis for the matching between stiffness and damping is proposed.The results show that the suspension can have non-linear stiffness characteristics such as ideal zero stiffness,arbitrary linear stiffness,and minimal or no stiffness.This has very important practical significance for improving the low-frequency vibration isolation performance of the self-propelled articulated seat suspension.(2)Self-propelled artillery seat-human system dynamics modeling.Based on theLagrangian equation,a 8 degree-of-freedom self-propelled gun seat-human system dynamics model is established.The model has 8 generalized degrees of freedom,and the geometric parameters are determined according to the relationship between the seat of the self-propelled gun and the human.Finally,the expressions of the dynamic equations of the seat-human system of 8 self-propelled guns are given.The model contains geometric nonlinearity caused by changes in the human body's torso angle and the nonlinear characteristics of the seat suspension.(3)Research on dynamic characteristics of self-propelled artillery seat-human system.The four kinds of excitation models including simple harmonic excitation,multi-frequency combined excitation,random excitation and shock excitation are established.Each excitation model is coupled with the seat-human system dynamics model,and the fourth-order Runge-Kutta method is used for numerical solution.This study studied the dynamic characteristics of a self-propelled artillery seat-human system.The results show that the suspension stiffness and damping characteristics have the most significant effect on the dynamic characteristics of the seat-human system compared to other parameters of the seat.This laid the foundation for the self-propelled artillery seat-human system parameter matching design.The nonlinear seat suspension design theory proposed in this paper and the new type of vibration isolation suspension based on the rotating rod mechanism are of great significance to reduce the transmission of vibration to the driver and improve the vibration comfort of the self-propelled gun.