Yukio Shigaki

Centro Federal de Educação Tecnológica de Minas Gerais | CEFETMG · Departamento de Engenharia Mecânica

Reaction–diffusion problems are found in several fields, such as fluid dynamics, heat transfer and electromagnetism. An accurate and efficient numerical method to obtain a solution to this class of problems is still a thriving topic of research. In this article, a new promising numerical strategy to solve this type of problems is proposed. The main...

The solar energy is one of the most promising energy sources today. In this context, the goal of this work is to produce selective surfaces for receiver tubes of parabolic trough collectors (PTCs). Ideally, solar collectors should have an absorbing surface that has high absorptance for radiation in the solar energy spectrum and, at the same time, l...

Roll deformation is an extremely important problem in strip rolling, all the more as the strip is thinner. It results in profile defects (the strip thickness varies in the transverse direction) and flatness defects (the strip exits the rolling mill wavy). This becomes a more and more stringent issue for modern, harder steels such as Advanced High S...

In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip) while both extremities do slip to accommodate the material acceleration of...

This paper presents a computer model for online prediction of the wear contour of grooved rolls in the round-oval-round pass rolling process based on semi-analytical equations and artificial neural networks (ANN). This wear may adversely affect the shape quality of final product and is a result of complex interactions of many variables in the rolli...

In this work it was analyzed the residual performance of Portland cement concretes, when cold after heat-treated up to 600°C. Granite-gneiss was used in the three concrete mix proportions as the coarse aggregate, and river sand with finesses modulus of 2.7 as the fine aggregate. Ultrasonic pulse tests were performed on all the specimens and ultraso...

Since the sixties, innumerable mathematical models have been developed to simulate flat rolling, specifically, to determine its width-wise profile. Among these, Pawelski, Rasp and others have developed a precise model that accounts for the influence of bending, shearing and flattening of the rolls which are crucial to calculate emergent strip-profi...