The rate of stable crack growth (SCG) in automotive steels sheets

The main aim of this paper is determining the stable crack growth (SCG) rate for automotive steel sheets. The SCG was monitored using the non-contact videoextensometry technique. CT (Compact Tension) specimens of three steel grades were loaded by eccentric tension under two loading conditions. The SCG characteristics including rate depend on steel grade, on the rolling direction as well as on the loading rate. Linear relation between the SCG rate and δR-curve slope was determined

The effect of annealing on mechanical properties of automotive steel sheets

This paper deals with mechanical properties of galvannealed automotive steel sheet. The composition of the zinc coating modifies as a result of the annealing after galvanizing, thereby its local mechanical properties change. Presented research is therefore aimed at determination the change in tensile properties of steel due to annealing, which is an important part of galvannealing technology. Annealing of galvanized steel samples was carried out at 500 °C with different holding times at annealing temperature. Changes in both tensile strength and normal anisotropy coefficient, a decrease of yield strength and an increase of ductility were found for examined steel

The effect of annealing on mechanical properties of automotive steel sheets

This paper deals with mechanical properties of galvannealed automotive steel sheet. The composition of the zinc coating modifies as a result of the annealing after galvanizing, thereby its local mechanical properties change. Presented research is therefore aimed at determination the change in tensile properties of steel due to annealing, which is an important part of galvannealing technology. Annealing of galvanized steel samples was carried out at 500 °C with different holding times at annealing temperature. Changes in both tensile strength and normal anisotropy coefficient, a decrease of yield strength and an increase of ductility were found for examined steel

Supply Chain Efficiency of Environmentally Friendly Microalgae-Based Biodiesel Production

Environmentally friendly algae-based biodiesel production includes biofuel extraction that represents a technological process which inflicts minimal damage to the environment or does not harm it. Biodiesel that is almost completely based on renewable resources can be utilized as one of the most promising biofuels, and it is environmentally safer than petrol-diesel for several reasons such as: 1. Microalgae have high photosynthesis efficiency and can grow very fast; 2. Microalgae can be cultivated without occupying farmlands, and thus it is possible to reduce the potential damage to the agricultural ecosystem and the traditional food webs; 3. Fresh water is not essential and nutrients can be supplied by wastewater and CO2 by gas combustion during cultivation; 4. Microalgae can be collected very quickly, obviously accelerating the biodiesel production process; 5. The property of their uniform cell structure with no bark, stems, branches or leaves make the commercial production attractive, thus making the operation and control of reproduction conditions much more practical; 6. The general properties as well as the physical biodiesel fuel properties from algae oil (e.g. density, viscosity, acid value, heating value, etc.) are comparable to those of fuel diesel. This paper investigates in detail this option presenting advantages, but also existing limits and gaps. Undoubtedly, incorporating the principles of supply-chain management enabled by information technology (IT) systems to support these processes is a more effective and efficient option to enhance the efficiency of algae-based biodiesel production

Numerical and experimental analysis of innovative support system of belt conveyor

The article processes an issue of the strength of a support system of a belt conveyor applying the numerical and experimental analysis approach. The support system of a belt conveyor is during the operation exposed to high impact forces due to the impact of the foreign objects. The methodology of the numerical analysis is based on the finite element modelling and according to the experimental analysis the boundary conditions are estimated. The results obtained using the numerical analyses are identical to the results from the experimental analysis. Maximal damage of the support system of a belt conveyor is estimated and according to the proposed methodology verified by the comparison of the experimental and numerical results, the design and optimization of the support system for the practical operation can be performed

Badania eksperymentalne i modelowanie matematyczne jako skuteczne narzędzia oceny uszkodzeń taśm przenośnikowych

Jedną z głównych przyczyn uszkodzeń taśm przenośnikowych są naprężenia dynamiczne, które często prowadzą do zakończenia cyklu życia taśmy. Naprężenia dynamiczne powodują pojawienie się funkcji wytrzymałości zmęczeniowej w warunkach oddziaływania na taśmę tkaninową obciążenia ścinającego. Problem uszkodzeń taśm przenośnikowych można rozwiązać prowadząc obszerne badania doświadczalne w warunkach laboratoryjnych na skomplikowanych, specjalnie do tego celu stworzonych urządzeniach. Celem prezentowanej pracy było określenie zależności między siłami w taśmie przenośnika a masą materiału spadającego na taśmę oraz wysokością zrzutu, w oparciu o dane z przeprowadzonych badań doświadczalnych. Pomiary eksperymentalne przeprowadzono na stanowisku badawczym zaprojektowanym w Instytucie Logistyki i Przemysłu Transportowego FBERG w Koszycach. Wyniki modelowania matematycznego wyraźnie pokazują, że proponowane modele regresji bardzo dobrze opisują rzeczywiste zachowanie taśm przenośnikowych podczas procesu produkcyjnego, w trakcie którego poddawane są one dynamicznym naprężeniom w wyniku oddziaływania siły uderzenia oraz sił rozciągających.One of the main causes of damage is their dynamic stress, which often ends the life-cycle caused end of conveyor belts. Dynamic stress leads to fatigue strength functions in shear loading of fabric conveyor belts. Damage of the conveyor belt can be solved by extensive experimental research in laboratory conditions on complex equipments made just for this purpose. The aim of the study is to determine the relation of power in the conveyor belt to the weight of the material which is falling onto a conveyor belt and to impact level height, which is based on data obtained in the experimental research. The experimental measurements have been performed on a test rig, which was developed at the Institute of Logistics and Transport Industry FBERG of Kosice. Results of mathematical modelling clearly say that proposed regression models describe real behaviour of the conveyor belts in productions during their dynamic stress as a result of the influence of shock and stretching forces very well

Ocena wpływu czynników na wytrzymałość na rozciąganie taśm przenośnikowych tkaninowo – gumowych

The Design of experiment (DOE) method was used in this paper to rubber conveyor belt tension testing. Using DOE method were from experimentally obtained data established effects of factors and interactions that affect the value of the measured strength and also were determined regression models, which apply input and output variables to the relation. The regression model presents the complete multifactor experiment that contains main factors and interactions.Metoda planowania eksperymentu (DOE) w artykule użyta do testowania napięcia taśm przenośnikowych tkaninowo – gumowych. Korzystanie z metody DOE były ustalonych poszczególnych czynników oraz ich interakcji ze danych uzyskanych w sposób doświadczalny. Czynniki i interakcje wpływające na wartość zmierzonej wytrzymałośći, a także określono modele regresji, wykazającego związki pomiędzy zmiennymi wejściowymi i wyjściowymi. Model regresyjny przedstawia kompletny wieloczynnikowy eksperyment obejmujący podstawowe zmienne oraz ich interakcje