Creep analysis of slightly oval cylindrical shells subjected to time-dependent loading, temperature and neutron flux

Abstract

Accurate creep analysis of unsupported, in-reactor fuel cladding containing initial ovality requires an analytic model which includes the effects of time-dependent variations in external pressure, cladding temperature and neutron flux. The purpose of this paper is to accomplish this objective by correcting and extending an earlier study that utilized the concept of body forces analogy to derive a set of finite difference equations governing the creep deformation of a slightly oval cylindrical shell. The present formulation also enables the analyst to investigate the influence of geometric nonlinearities on the deformation via application of the pseudo-load technique to the equilibrium equations. Numerical results demonstrate the effect of variations in neutron flux, external pressure, cladding temperature, geometric parameters, mesh size and solution time step on collapse time.