AN ANALYTICAL MODEL FOR PREDICTING RESIDUAL-STRESSES IN PROGRESSIVELYDEPOSITED COATINGS .2. CYLINDRICAL GEOMETRY

An analytical model is presented to predict the residual stress distri butions in progressively deposited coatings with cylindrical substrate s. Misfit strains, due either to the deposition stress or to different ial thermal contraction, set up forces in the longitudinal direction a nd interfacial pressures in the radial direction. Use of stress-strain relationships in the longitudinal and hoop directions allows these fo rces and pressures to be evaluated. A layer-by-layer approach is emplo yed to determine the stresses set up in the coatings during deposition . Predicted stress distributions are presented for three plasma spraye d systems. Comparisons with a numerical model, of the type presented i n Part 1 for planar systems, have not been made, but the behaviour pre dicted is intuitively as expected. In addition, the model has been app lied to predict the through-thickness stresses in specimens with plana r substrates for the case when bending is not allowed, by artificially assigning a large inner radius to the substrates. (C) 1997 Elsevier S cience S.A.