ENGINEERING RESEARCH
Abstract
A numerical method of calculating deformations and stresses in an elastic solid propellant grain having a circular perforation and flat ends and bonded to a rigid motor case was used to calculate stresses and deformations caused by axial acceleration loading. Two grain end situations were considered: both ends free and one end free with the other bonded to the motor case. The dimensionless displacements of critical parts of the grain were calculated as functions of the inner-to-outer radius ratio a, the length-to-diameter ratio lambda, and Poisson's ratio nu The dimensionless radial and shear stresses at the propellant-motor case interface were also calculated as well as the percentage of total load carried by the bonded end for grains bonded on one end. The equations of motion of a viscoelastic solid were reduced to a single Poisson equation by assuming that the displacements do not vary with the coordinate direction along which the acceleration is applied. A general solution to this equation was obtained for hollow cylinders of infinite length having generators parallel to the direction of acceleration and transverse cross sections with p( p not = 0) axes of symmetry. The solution was applied to solid propellant grains of infinite length having star-shaped internal perforations to determine the stresses and deformations caused by axial acceleration under the conditions of zero displacement at the outer boundary and zero surface stresses at the inner boundary.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 19, 1963
- Accession Number
- AD0403443