NUMERICAL STUDY FOR LUBRICATION EFFECTS IN METAL FORMING THROUGH THE PROCESS OF BARREL COMPRESSION

Resumo

In metal forming process, friction is one of the most important factors, as it has a great influence
on the shear stress behavior. The shear stress pattern determines the material’s properties, structures and energy
requirements. In addition, the importance of friction analysis also arises from the efforts to which the material
is subjected and from the reaction force on the machinery used, with direct implications for the efficiency of
the manufacturing process, the cost and the time employed. Therefore, analyzing ways to reduce the damaging
consequences of friction is extremely important. In this sense, the analysis of lubrication becomes too relevant
since, through the reduction of friction, it is possible to increase the efficiency in the metal forming process.
Thus, the present study aims to relate the effect of lubrication on the shear stress of the specimen with the
analysis using the computational method of Finite Elements in the Barrel Compression process. For this purpose,
the friction coefficients of the main lubricants on the market were used and the effects on the test results were
simulated.
Therefore, numerical analysis was performed in the Ansys Structural Analysis® software environment. Thus,
the CAD models for the specimen and for the test matrix were created. In addition, a mesh evaluation was made,
scoring the effects arising from the precision change. Besides, the boundary conditions were also scored, using the
various tools that the software offers. It should be noted that the program resolution algorithms were verified, as
well as their convergence criteria.
Finally, in possession of the computer simulation results, their validation is sought by comparing them with
the theoretical expected for the same test, but in the absence of lubrication. In this way, gains from surface
lubrication are quantified and the extent to which the change in lubricant causes a relevant consequence in shear
stress is also measured. This article, therefore, seeks to be another source of research in the promising area of
metal forming analysis.