Reliability of Thermally Loaded Cylinders

Abstract

Cylinders often contain fluids at various temperatures. Temperature gradients develop across the cylinder which in turn produce thermal stresses. Using a perturbation technique, expressions for means and standard deviations of thermal stresses in cylinders are presented in this paper. These expressions include the probabilistic effects of changes due to inner and outer radii, modulus of elasticity, Poisson’s ratio, coefficient of thermal expansion, and temperature. It is found out that the cylinder is more sensitive to the geometrical changes than the mechanical and thermal changes. It is also noticed that the effect of variation in the inner radius is more than the outer radius at the inner half of the cylinder. On the other hand, the effect of variation in the outer radius is more than the inner radius at the outer half of the cylinder. Probabilities of failure are calculated for normal and log-normal distributions.