Flexibility Analysis of Cylindrical Panels of a Hypersonic Launch Vehicle in a Ballistic Trajectory for Separation Loads

Abstract

Nose cone and cylindrical panels of a hypersonic launch vehicle encapsulates cruise vehicle during boost and coast phase of ballistic trajectory. At predetermined altitude and Mach number panels open, rotate about a hinge and separate from launch vehicle so that cruise vehicle can be ejected for autonomous flight. Objective of the study is to ensure that cylindrical panels are integral while rotating about the hinge and once released, move away from cruise vehicle. Design objective is achieved by performing a transient dynamic analysis of cylindrical panels with varying pressure loads using commercial finite element software ANSYS. In this analysis, a pair of cylindrical panels is modeled simultaneously. Hinged boundary condition is simulated up to release angle. Panel release condition is simulated by removing the boundary conditions at the appropriate time step. Stress distribution on panels and panel deformations are evaluated. Observations from study are, for high release angle, panels fail and disintegrate however at very low release angle it tends to interfere with the cruise vehicle. Design objective is met by a release angle of 10 deg. Rear end ring thickness is increased to reduce stress and large deformations. Factor of safety on panels are within allowable limits for a release angle of 10deg.