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Granica wytrzymałości konstrukcji zmechanizowanej obudowy ścianowej na przykładzie badań numerycznych

Szurgacz Dawid, Chyrowski Piotr, Trzop Konrad

Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie

2023

nr 9

2--8

The process of designing a longwall powered support is extremely complex and requires many operations related to the creation of a complete machine. The powered support section is one of the basic elements of the longwall system. The implementation of the support that meets the guidelines of the manufacturer and user, requires an endurance analysis at the design stage conducted according to the regulations in force. The main objective of the research was to perform the analysis of the ultimate strength of selected elements of the designed powered support section. The research was carried out with the use of special software that uses the finite element method. The article presents the analysis of the strength limits done with the help of the finite element method, determining the strength of selected elements of the longwall support section. The solutions proposed included changes in the structure and properties of the material in the design process. The aim of the proposed solution was to obtain a model with strength value that meets safety standards. The research results are a valuable source of knowledge for designers. Solutions of this type set examples for spatial models of the longwall support section being designed nowadays. The analysis presented in the article, together with the results of the research and the conclusions resulting from them, may improve the safety and effectiveness of powered supports.

W artykule przedstawiono badania, których celem jest analiza wytrzymałości granicznych konstrukcji obudowy zmechanizowanej. Przeprowadzono je z wykorzystaniem metody elementów skończonych. W oparciu o wyniki badań zaproponowano model spełniający normy bezpieczeństwa.

A Study of The Properties of Forming Mixtures Containing Polystyrene Wastes

Dan Olena, Trofimova Larysa

Journal of Casting & Materials Engineering

2021

Vol. 5, no. 2

14--19

Expanded polystyrene is widely used as a material for packaging, in modern construction as a heat and sound insulation layer, in thermal insulation systems for buildings, as well as tanks and pipelines. It is additionally used in foundry engineering for the production of models which are gasified during the production of castings from ferrous and non-ferrous alloys under the contact with liquid metal. The use of expanded polystyrene products is associated with waste generation, both in production and in consumption. About 40–50 kg/person of polystyrene waste is generated per year. The peculiarity of polymeric wastes is their resistance to aggressive environments. They do not rot and the destruction processes in natural conditions proceed rather slowly, with the formation of harmful substances that poison the environment. Therefore, the problem of the processing of waste from polymeric materials is of great importance, not only from the standpoint of environmental protection, but also due to the fact that in conditions of a shortage of polymer raw materials, this waste becomes a powerful raw material resource. This article describes the prospects for recycling expanded polystyrene wastes in foundry engineering. In this work, the properties of molding and core sands containing a combined binder, consisting of a solution of expanded polystyrene wastes in turpentine and clay were investigated, and their main characteristics (weight during stretching and crumbling) were determined. Molding and core mixtures, which contain only a binder in the form of a solution of expanded polystyrene in turpentine, have a crude strength of not more than 0.01 MPa. The introduction of a mixture of clay in the amount of 2–3% allows a crude strength of the mixture of up to 0.05 MPa to be obtained. After drying, the investigated mixtures containing a solution of expanded polystyrene wastes and clay have a tensile strength of up to 2.1 MPa. Mixtures into which a solution of polystyrene wastes and clay was introduced have an insignificant gas capacity and satisfactory gas permeability.