Transient Motions of Solid Propellant Motor Casing at Launch Vehicle Liftoff

Use of the composite materials for manufacturing of thin-walled elements of launch vehicle gives several advantages in comparison with traditional materials. The main advantages are high strength of the structure with small mass. Solid propellant motor casing manufactured from carbon-filled plastic is considered. This material is orthotropic. The purpose of this study is development of numerical methods for dynamic deformation of solid propellant motor casing, which is considered as thin-walled structure. The internal impulse excitation acts on the casing of launch vehicle. The compound spherical-cylindrical-spherical shell describes the considered casing under the action of impact pressure. The shear theory is used in simulation. The software for this problem calculation is developed. The verification of the software is carried out by comparison of the obtained results with finite element calculations in the commercial software ANSYS. Dynamic stress state of the motor casing is carried out. The behavior of displacements projections and stress tensor in time are the results of this analysis. Time of growth of impact pressure is equal to 5 ms, Note, that the maximal values of displacements and elements of strain tensor are observed at 10 ms. Thus, the displacements and stresses continue to increase, when the impact pressure stops to increase.