Simulation Study On Axial Separation Of Missile Fairing

Fairing is an important structure of missiles and rockets,which is responsible for ensuring the good aerodynamic shape of the launcher and protecting the payload from the outside environment during flight.The successful load launching is determined by whether the faring can separate normally.With the rapid development of national defense,the requirement of missile carrying capacity is continuously improved,so that the geometric dimension of missile fairing increases rapidly,and the structural stiffness decreases.The missile fairing separation is generally in the axial and monolithic way,and the coincidence of distance between the projectile and the missile fairing will be longer.Consequently,the change of the relative attitude of the two and elastic deformation of the faring in the process of separation will cause the security space fairing is reduced and the increasing risk of collision.The large vacuum tank can be used to simulate the high-altitude environment,but the current size of the vacuum tank in our country can't meet the requirements of fairing separation experiment.The ground experiment will be affected by the factors such as air resistance and gravity,which causes the experimental data can't reflect the separation characteristics at high altitude.Therefore,the computer simulation of the altitude separation process of fairing can provide important reference data for technicians.This paper,based on multi rigid body dynamics,finite element theory and multi-body dynamics,studies the kinematic characteristics and the elastic deformation of the fairing in the axial and monolithic separation way by using ADAMS and ABAQUS software to do the simulation analysis.First,the rigid multi-body dynamic model of fairing separation is established by using Newton-Euler Equation and solved to obtain the theoretical kinematic characteristics of rigid body fairing.And ADAMS software is used to ensure the accuracy of the simulation results.Secondly,the finite element model of the fairing separation is built by using the commercial software ABAQUS and the separation process is simulated and analyzed.The separation characteristics of elastic body fairing and the influence of the arrangement of strengthen structure and the selection of materials on the elastic deformation of the fairing are obtained,which can determine whether the fairing can collide with the projectile.Thirdly,a flexible multi-body dynamic model of fairing separation is established to simulate separation process by using ADAMS which is imported a modal neutral file calculated by ABAQUS.The influence of modal number selection on the simulation results is studied.Compared with the results of the finite element model,the differences between the two models are compared.Finally,the factors are studied,which can influence the relative attitude between the fairing and projectile,including the explosion of the single explosion bolt,the lag of separation rockets' ignition time and thrust deviation of separation rockets.Separation characteristics of fairing and relative attitude are obtained,which can determine whether the fairing can separate safely.