The effect of creep on the stresses in the walls of a pressure vessel

Abstract

It is the purpose of this thesis to consider the effect of creep on the stresses in the walls of a pressure vessel caused by variations in temperature between the inside and outside walls of the vessel. A simple model whose behavior is the same as the wall of the pressure vessel when subjected to the imposed load is developed and equations relating to the solution of the problem are presented for the case when the material creep law is of the form ℰ= Knσ n The equations are then solved for N having values of 1 and 2. While the study does not attempt to solve equations for N = 3, 4, and 5, due to the mathematical complexity of the resulting equations, the author does discuss the determination of the initial stress on the model and also develops a formula to determine asymptotic values for the stress on the model when t→∞ for all values of N.