Spectrum Analysis Of Solid Rocket Motor With Viscoelastic Grain

Solid rocket technology is a subject covered a wide range of cutting-edge technology. While the viscoelastic solid rocket engine and is one of the most important fields. Due to the role of grain and requirements in the preparation of required processing all types of materials mixing and and the properties of the materials along with complex; and the grain of material properties on the viscoelastic analysis and research through the combination of practical test has important significance. And plays a decisive role for the design and calculation of the rocket in response to the dynamic of the rocket in the working state. So the modal of the rocket as a whole analysis of random vibration spectrum analysis of simulation results the rocket overall design and safety design to leading. This paper combined with test and viscoelastic theory, the measurement and fitting of the basic parameters of viscoelastic propellant; combined with the obtained results with the finite element analysis method and on solid rocket engine for static analysis and dynamic analysis, will eventually get the results and parameters to be applied.The constitutive relationship and Laplasse transform combining the basic theory of viscoelastic integral in this paper, pushing into the constitutive equations of Prony series can be used in the form of finite element. The results obtained from the experiments are used to fit the constitutive relation of the MATLAB, and the Prony series of the actual test results are obtained. And then the experimental parameters are introduced into the finite element analysis.In the experiment, this paper used the high precision thermal dynamic analyzer and the three-dimensional visual displacement detector to collect the data of the time function curve of the parameters of the model solid rocket. Then the data is fitted by the mathematical software MATLAB, and the response function is obtained. Based on the theoretical basis of the basic theory of viscoelasticity and the isotropic material, the fitting function is derived for the basic parameters such as elastic modulus and Poisson’s ratio of the material.In the measurement of the Poisson’s ratio of solid rocket, two methods are used to measure the Poisson’s ratio by using the theory of viscoelasticity. The first one is the calculation of the Poisson’s ratio of the transverse strain and relaxation modulus obtained by the test. The second kind of integral expressions of Poisson’s ratio is derived by the transformation of tensile relaxation modulus and shear creep compliance in Laplace domain. Non contact measurement method is used in measuring position. In this paper, by using the visual measurement, the displacement analysis of the sample after speckle processing is carried out. Finally, the result will not affect the properties of the material and can get the displacement of each direction.Using the finite element software ANSYS for finite element analysis of the rocket as a whole; observation of static load and deformation of the viscoelastic correspondence; then the whole three-dimensional rocket for modal analysis and random vibration spectrum analysis, finally get the overall structure of the ring oscillator, the oscillation frequency and the dangerous position of random response spectrum.The research results and conclusions of this paper have some significance for the viscoelastic finite element analysis and material parameter collection of solid rocket motor grain.