Mérnöki és Informatikai Megoldások

Models for symmetric cold rolling of an aluminum sheet

János György Bátorfi — 2022-12-12

In the current work, the behavior of Al alloys during cold rolling is studied with the help of numerical approaches such as Finite Element (FEM) and Flow-Line (FLM) Models. The applicable simplifications for each method have been summarized in this contribution. For simulating the process of rolling, a material model was employed, which is based on the measured values obtained from the tensile test. The results of the conducted rolling experiments were compared with the numerical simulations performed by employing the experimental material models. The analysis of simulated and experimental data allowed us to evaluate the friction coefficient. A relationship has been established between the minimum friction coefficient necessary for rolling and the estimated one and this result is in a good agreement with the counterpart reported in literature sources. The established method was used for the evaluation of the characteristic components of the strain, namely the normal, shear, and equivalent components. The comparative study between recorded measurements and simulations indicates that both the FEM and FLM models can be successfully applied to simulate the symmetric cold rolling process of aluminum with sufficient accuracy.

Numerical simulation of the performance of an asymmetrical airfoil under extreme weather conditions

Ibrahim Rotich — 2022-12-12

This paper presents a numerical study of icing of a NACA2412 airfoil and the aerodynamic performance of the airfoil with ice accretion. The study analyzes the effects of liquid water content, accretion time and varying angles of attack (AoA) up to 20⁰ on ice accretion and, consequently, on the aerodynamic coefficients of the airfoil. The free stream velocity and air temperature were kept constant in the simulations. Results revealed that the ratio of lift and drag coefficients was the highest after a short accretion time (i.e., about 20 minutes), but then it decreased significantly with accretion time. Ice accretion increased with time; its mass was the greatest at 10⁰ of AoA. The results can be beneficial for designing blade shapes to optimize wind turbine performance during adverse weather conditions.

CAD modelling of the chip shape in case of ball-end milling

Bálint Varga — 2022-12-12

The manufacturing of free form surfaces is a common task in the field of mould and die manufacturing. The changing circumstances of the finishing milling with ball-end milling cutter has effect on the shape and the volume of the chip, the load of the cutting tool and the generated surface roughness. The aim of the article is to investigate the changing of the chip thickness and volume in case of ball-end milling by 3D CAD modelling, and to analyse the changing of the circumstances in case of milling of a convex and a concave surfaces.

Investigation of materials flow during the manufacturing process by experimental evidence and numerical approaches

János György Bátorfi — 2022-12-12

In this paper, the modeling possibilities applicable to rolling processes were summarized, with particular reference to finite element models (FEM) and different flow-line models (FLM). The results of the analysis suggest that the different models are suitable for the study of deformation processes during cold rolling. Furthermore, the possibilities for the extension of the FLM model are summarized.

Investigation of cutting force components and surface roughness in face milling with different cutting ratios

Csaba Felhő — 2022-12-12

During the face milling process, the choice of technological parameters plays an important role. The two most important parameters are the feed and the depth of cut, the ratio of which is also called the cutting ratio. The main topic of the paper is to examine how different values of the chip ratio affect the components of the cutting force and the roughness of the machined surface. It is also shown how important it is to know the exact geometry of the cutting insert, as well as - in the case of cutting with multiple inserts - the knowledge of the run-out between the individual inserts. Based on the performed investigations, it was determined that the use of a chip ratio close to 1 is not recommended either in terms of cutting force components or surface roughness.

Accomodation of deformation in rolled Aluminium

Gyula Pál — 2022-12-12

The current as well as the future industrial market for Aluminium (Al) is huge and various research is being under work regarding the usability of Aluminium. However, during the deep drawing of Aluminium several issues can be developed and some of them are originated from the fundamental material properties. One of these factors is the material texture, which is the preferred orientation of the constituent polycrystalline Al, and the characteristic texture is affected by different rolling and annealing schedules. To investigate the material texture, symmetric and asymmetric rolling trials were performed on a commercially available Al 1050 sample. Energy-dispersive X-ray Spectroscopy (EDX), and Electron Backscatter Diffraction (EBSD) scanning has performed to determine the material composition and the crystallographic orientations of the investigated samples.