Analysis On Structural Integrity Of Complex Charge With Large Length-Diameter Ratio

Solid rocket motor is one of the key components of all kinds of missiles nowadays.The performance can directly affect many parameters of missiles.The propellant in solid rocket motor is the power source of the whole missile,and also directly affects the range,speed and other indexs of missiles.Throughout the whole process of missile manufacture,transportation and launching,propellant is affected by many kinds of loading,such as the temperature amplitude loading caused by temperature change,the vibration of the moving vehicle,the acceleration,pressure and other loadings caused by missile launching.The quality of propellant can also directly lead to whether the missile can be successfully launched.Therefore,the propellant can be propelled under certain circumstances.The performance of the agent also needs to be studied and analyzed in order to make its performance in an excellent state.In this paper,the finite element simulation of a certain type of solid rocket motor is carried out,and the mechanical response behavior of the charge is mainly analyzed.The main contents are as follows:(1)Parametric modeling program based on Python language in ABAQUS.For the internal charge of this type of solid rocket motor used in this paper is special shape and complexity,it adopts the combination of star hole segment and circular hole segment.Because of the need for structural integrity analysis in this paper,it is necessary to establish a variety of models when modeling and the parameters such as the local size of the charge will change,so developing parametric modeling program will can short the modeling time and improve the work efficiency.(2)The experimental verification of the second development of UMAT for the constitutive model.Because the solid rocket motor in design phase can not be verified by real experiments,it needs to be pre-analyzed by the finite element numerical simulation method.In order to increase the reliability of the analysis,the mechanical response of the charge can be calculated more accurately.It is necessary to compare the structure with the simulation results through uniaxial and multi-step tension-relaxation experiments,and then verify the accuracy of the selected UMAT material subroutine.(3)The influence of length-diameter ratio and m number of charge on the structural integrity of charge under temperature loading.In order to study and analyze the main factors that affect the structural integrity of thecharge,the effects of the length-diameter ratio and the number of m on the mechanical response of the charge were studied by comparing the multi-group length-diameter ratio and the number of m under low temperature loading.At the same time,the solid rocket motor with large length-diameter ratio was subjected to the combined action of internal pressure under low temperature and high temperature loading respectively,and the influence of length-diameter ratio on the mechanical response behavior of charge under different temperature conditions was analyzed.(4)Optimum design of local structure of charge under combined action of temperature loading and internal pressure loading.In order to improve the mechanical response level of engine charge with large length-diameter ratio,this paper optimizes the local position of the charge by applying the combined action of temperature loading and internal pressure loading,and by changing the value of local parameters,the better value is selected.Increasing the structure of umbrella disc and stress release cover,it can improve the mechanical properties of the charge.At the same time,the mechanical response of the local structure is studied and analyzed.