Dynamics Characters Research On Chain Shell Feeding Platform Of Large Caliber Naval Gun

Large-caliber naval guns have played a significant part in combined operations of navyand army in recent years. The shell feeding stability must be taken into account in the designof large-caliber guns to ensure the continued fighting ability. Aiming at the problem,dynamics modeling, simulation and optimization of the chain shell feeding platform oflarge-caliber naval guns were researched. Furthermore, its dynamics characteristics wereanalyzed to identify the main factors that cause shells rocking and then the system parameterswere optimized to improve shell feeding stability and reliability. The main contents is asfolllows:According to the structure of the chain shell feeding platform of large-caliber naval guns,a rigid-flexible hybrid dynamic model with contact-impact was established. The modelincludes the multi-body rigid model with flexible joints of the roller chain in shell feedingplatform, the flexible body model of shell-clasping leaf springs based on absolute nodalcoordinates method and points contact-impact model of the contact-impacts between rollersand sprockets and that between shell-clasping leaf springs and shell based on Hertz contacttheory. The methods on stiffness coefficient determination of felxible joints and thepre-defrorm process of shell-clasping leaf springs were studied afterward.Based on the rigid-flexible hybrid dynamic model with contact-impact, thecontact-impact algorithm and the flexible/rigid switching method of shell-clasping leafsprings were studied. In the contact-impact algorithm, a quick method to search thecontact-impact between the sprocket with complete tooth profile and roller was proposed. Inflexible/rigid switching method of shell-clasping leaf springs, the method to determine switchtime was researched.According to the dynamic simulation of shell feeding platform with rigid-flexible hybriddynamic model with contact-impact, ADAMS users subroutine was developed. On this basis,the frequency-domain and time-domain vibration characteristics of shell feeding platform areanalyzed. In frequency-domain analysis, the effect of the weight of shell container and thethickness of shell-clasping leaf spring on vibration frequency and frequency response of shellfeeding platform was discussed, and the variation of vibration frequency and frequency response in feeding process was obtained. In time-domain analysis, the effect of the weight ofshell container and the thickness of shell-clasping leaf spring on meshing impact betweenroller and sprocket as well as the rocking of each shell in feeding process were obtained.In order to improve the shell feeding reliability of feeding platform, the dynamicoptimization of shell feeding platform was performed. By defining the increase of theminimum clearance between shell bottom edge and inner wall of hoist at the moment whenshell passes its entrance as optimization objective, the dynamic optimization model wasestablished. Considering the shortcomings of existing optimization method in dynamicoptimization of the complex multi-body systems like shell feeding platform of large-caliberguns, a hybrid optimization algorithm of two-population genetic algorithm and particle swarmalgorithm is proposed. The hybrid optimization algorithm was introduced into iSIGHT byprograming, and then ADAMS/iSIGHT joint simulation was performed to accomplish shellfeeding platform dynamic optimization.