Stress Analysis for a Nonlinear Viscoelastic Cylinder With Ablating Inner Surface

An approximate constitutive equation for nonlinear viscoelastic incompressible materials under small finite deformation and for short time ranges has been derived by Huang and Lee [1]. The resulting equation is applied to solve the problem of a pressurized viscoelastic hollow cylinder bonded to an elastic easing. This problem is of notable technical interest in solid propellant stress analysis, since it is a close model to represent a cylindrical propellant grain in a solid fuel rocket under firing condition. The method used by Huang and Lee is appropriate for numerical calculations when the boundaries of the cylinder are nonablating. To consider one step closer to the real situation, the inner surface is often assumed to be ablating and hence time-dependent. It is then the purpose of the present paper to extend the analysis to a cylinder with moving inner surface.