Paint coating characterization for thermoelastic stress analysis of metallic materials

Abstract

In thermoelastic stress analysis (TSA) it is normal practice to coat metallic specimens withblack paint to enhance and standardize the surface emissivity. It is assumed that the paintcoating has no effect on the thermal emission from the specimen, but it is well known that theresponse is sensitive to paint coating thickness, particularly at higher frequencies. In this paperthe effects of loading frequency and paint coating thickness on the thermoelastic response areinvestigated. The thermoelastic response is compared to theory, and optimum test conditionsand coating characteristics are suggested. The motivation for the work is to develop aTSA-based means of residual stress assessment, where the measurement of much smallertemperature changes than those that are resolved in standard TSA is required; therefore theanalysis is much more sensitive to the effects of the paint coating. However, the workpresented in this paper is relevant to a wide range of TSA investigations and presents data thatwill be of interest to all practitioners of TSA