Research On The Longitudinal Expansion Technique Of Rocket Towed NET System

This paper is mainly concentrated on dynamics of the Rocket Towed Net System(RTNS)by flexible multi-body dynamics theory.The simulation of the RTNS flying has been done and the flying test proves the conclusions in this dissertation.The RTNS,a complex,accumulate and efficient system,is towed by a solid rocket motor,which the net will cover the target area with ammunitions on it.With the explosion of the ammunations,all the mine in the target area will be cleaned up.The main contents include the dynamical modelling of the RTNS,characteristics of system trajectory,the design of the rocket and net,research of similarity,the math model and calculation of system launching,the mechanical properties of the main parts,the flying test of the system.The contents of this research are shown as following:1.This is the first time which the Flexible Multi-body Dynamics theory has been used in the analysis of the RTNS.Based on the rigid model of the rocket and the Absolute Nordal Coordinates Formulation(ANCF),the model of the RTNS is built.2.A group of ballistic parameters are gotten by the RTNS exterior ballistic design.These parameters are used for the design of the rocket.By the theory of the solid rocket motor design,a set of design process is built and tested by a mature motor product.Based on the similarity theory,? theory,the similarity criterions are built for the net structure.And the structure parameters,like the length and linear density of the net,are calculated by the numerical method.3.Then,the emission theory model for the RTNS is built,and the launching angles of the ground launch and the bin-up launch are determined.Thses two launch ways are compared by the result of the numerical calculation.In additional,the relationship between the rocket flying stability and the structure parameters of the wire rope are analyzed by the simulation work.And also,the elasticity of different tripping line material,which has impact on the longitudinal expansion of the RTNS,is analyzed.4.With the analysis of the wirerope constitutive model under impulsive load,the quasi-tensile test is finished and the mechanical properties of the RTNS wire rope has been gotten.And the mechanical properties of the net material,net with ammunition structure,the tripping line and the material of the stand bars are achieved by the same test way.These mechanical parameters play an important role in the simulation work.Using the force method to calculate statically indeterminate structures on the net,the relationship,between the tensions on the wire rope and net,has been researched.5.The flying test is done for the RTNS.Comparing the results between simulation and test,all the conclusions are verified as correct.In the future research of the RTNS,this dissertation will provide a good foundation.