Marcin Hojny

The paper presents example results leading to develop multiscale 3D methodology of mechanical properties prediction for steel deformed in the temperature range close to solidus line. Conducted experiments and simulations confirms the need to seek new methods to obtain precise characteristics in the context of detailed computer simulations.

The main goal of the paper is modelling of phenomena accompanying the steel subjected to deformation in very high temperature. Analysis of the phenomena in solid surface part and semi-solid core is necessary due to inhomogeneity of material properties in both the zones of the sample. Experimental basis of the work were TESTS done in IMZ Gliwice using Gleeble 3800 physical simulator. The interpretation of the tests was done using Def_Semi_Solid software. This program allows the numerical analysis of steel behaviour during deformation of axial-symmetrical samples at very high temperatures. The paper presents the comparison of experimental and numerical results.

The condition of steel deformation in a semi-solid state should be as isothermal as possible due to the very high sensitivity of material rheology to even small variations of temperature. The basic reason for uneven temperature distribution (melting zone) inside the sample body on the Gleeble thermo mechanical simulator is the contact with cold/warm copper handles. The semi-solid conditions in central parts of the sample cause even greater temperature gradient due to latent transformation heat. Such non-uniform temperature distribution is the source of significant differences in the microstructure and, hence, in material rheological properties. In the paper example results of tomographic studies were presented for both experimental variants (with warm and cold handles).

This paper shows example results of computer simulations supporting the production process of sink. Design and verification of deep drawing process and tools design were carried out using finite element models implemented in Inventium Suite. Wrinkling and fracture of the material were the main phenomena subjected to the investigation using numerical analysis. A number of computer simulations were carried out in order to eliminate defects and analyze the shape of the final product.

W artykule przedstawiono hybrydowy model dedykowany symulacjom przepływu ciekłego metalu i krzepnięcia. Opracowane rozwiązanie jest kluczowym elementem rozwijanej koncpecji zintegrowanego modelowania łączącego zalety symulacji fizycznej i komputerowej, zaś sama koncepcja stanowi fundament warsztatu naukowego zorientowanego na procesy wysokotemperaturowe (bliskich linii solidus). Przedstawiono przykładowe wyniki symulacji testowych, wskazujących na poprawność przyjętych założeń modelowych.

The paper deals with visualization of results for simulation of a deformation process of a sample with a mushy zone. The numerical model consists of three basic subsystems: the mechanical, thermal and density changes parts. These describe both solid and semisolid deformation states. Taking into consideration their specific distribution graphical visualization is very helpful for understanding the course of the process. Moreover, a three-dimensional presentation is applied in various fields, ranging from medical imaging systems to technological processes assistance to scientific visualizations and entertainment. The stereoscopic imaging technique is still being developed. It is based on the idea of showing each eye the same scene from a bit different perspective. As an effect the illusion of depth is created due to the way the two images are interpreted by the human brain. Stereoscopy is not a new concept, but in the past few years a significant increase in the interest in this method of visualization could be observed. It is caused by computer and audio-visual technology development. In the paper several techniques of creating stereoscopic images are presented together with their physical bases and devices providing such functionality. The use of projection equipment and possibilities of its application to visualization of semi-solid steel deformation is discussed. Apart from that a description of an implementation of OpenGL specification for stereoscopic presentation of computer simulation results is provided.