Transient analysis of thick-walled piping under polynomial thermal loading

The transient response of a thick-walled pipe subjected to a generalized excitation of temperature on the internal surface was derived using Duhamel's relationship. Generalization of the temperature excitation was achieved by using a polynomial composed of integral- and half-order terms. In order to avoid the evaluation of recurring functions in the complex domain, Laplace transformation and a 10-term Gaver-Stehfest inversion formula were used to perform part of the necessary integrations. Excellent agreement between the derived relationships and existing analytical and finite-element solutions was seen for a thick-walled cylinder subjected to an asymptotic temperature rise on the exposed surface. As intended, the use of a smoothed polynomial allows the incorporation of empirical date not easily represented by standard functions. Moreover, the resulting relationships are easily programmed and can be used for a wide range of nuclear, piping, and cylindrical vessel applications.