In recent years, functionally graded material (FGM) has been widely explored in coating technology amongst both academic and industry communities. FGM coatings are suitable substitutes for many typical conventional coatings which are susceptible to cracking, debonding and eventual functional failure due to the mismatch of material properties at the coating/substrate interface. In this study, a thick spherical pressure vessel with an inner FGM coating subjected to internal and external hydrostatic pressure is analyzed within the context of three-dimensional elasticity theory. Young’s modulus of the coating is assumed to vary linearly or exponentially through the thickness, while Poisson’s ratio is considered as constant. A comparative numerical study of FGM versus homogeneous coating is conducted for the case of vessel under internal pressure, and the dependence of stress and displacement fields on the type of coating is examined and discussed
An inverse analysis using artificial intelligence based on the guided ultrasonic waves is proposed for effective identification of damage in thick steel beams for the purpose of structural health monitoring applications. Parameterized modeling for finite element analysis is applied to constitute the damage parameter database cost-effectively. For signal processing and feature extraction, wavelet transform is employed. A novel feature extraction technique, damage characteristic points, is applied to constitute the database for pattern recognition procedures. Using the extracted metrics, a multilayer feedforward artificial neural network under supervision of an error-backpropagation algorithm is developed and trained. The generalization performance of the artificial neural network has been examined experimentally. Results illustrate that the proposed metrics together with artificial neural network technique are powerful tools for effective identification of damage in the case of thick structures.
Development of new coating systems has been an important issue over the years with the motivation\ud
of extending the effective life of mechanical elements. For this intent, functionally graded materials have\ud
been recently used in a variety of applications as promising replacements for conventional coatings. In the\ud
present study, a hybrid coating system taking advantage of graded composition concept is proposed to enhance\ud
the through-thickness stress distribution within a double-sided coated circular thick homogeneous plate. The\ud
coating system is composed of two main layers: an external homogeneous layer and an interlayer between\ud
the external layer and the plate, with graded material composition. All layers are modeled within the context\ud
of three-dimensional elasticity theory, and an elasto-static solution is obtained by using suitable potential\ud
functions.Accuracy and reliability of the proposed analysis is investigated by comparison with results obtained\ud
in the literature, as well as with the results of a three-dimensional finite element simulation. Comparative study\ud
shows the inherent advantages of the present hybrid coating system over the conventional homogeneous coating\ud
or the functionally graded coating layers
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.