Transient temperature response in functionally gradient materials

The temperature response in functionally gradient materials (FGM), subjected to pulseor stepwise heating at the front surface, is evaluated. Applicability of the approximate solution for the temperature response is investigated by comparing it with an exact analytical solution for the FGM in which thermophysical properties have certain profiles. When the FGM is composed of conventional solid materials, appropriateness of the approximate solution for the FGM is demonstrated as far as the temperature response near the rear surface is concerned. The approximate solution is also compared with the solution for the multilayered material. It is shown that an eight-layered material can be regarded as an FGM, as far as the temperature response at the rear surface is concerned, and that the approximate solution can predict the temperature response within 6% error. Because of its simplicity and fair degree of agreement, the approximate solution is anticipated to be used not only for qualitative but also for quantitative prediction of the temperature response near the rear surface of the FGM in engineering applications.