Nauki Techniczne

Archive of Mechanical Engineering

Zawartość

Archive of Mechanical Engineering | 2018 | No 2 |

Abstrakt

This article investigates the solution of exponentially graded (EG) thick rectangular plates resting on two-parameter elastic foundations according to a trigonometric plate theory (TPT). This theory includes the effect of both shear and normal strains thickness without needing to any shear correction factor. The displacement fields contains initial terms of a power series across plate thickness as well as additional trigonometric terms. The material properties of plate is graded such that Lamé’s coefficients convert exponentially in a given constant orientation. Equilibrium equations according to the EG plate resting on Pasternak’s foundations are derived. The solution is obtained by using Navier’s technique. Numerical results for the EG thick plate on elastic foundations are presented, and compared with those available in the literature. The influences of Winkler’s and Pasternak’s parameters, side-to-thickness ratio, inhomogeneity parameter and aspect ratio on the bending responses of EG plates are investigated.
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Abstrakt

Experimental design and computational model for predicting debonding initiation and propagation are of interest of scientists and engineers. The design and model are expected to explain the phenomenon for a wide range of loading rates. In this work, a method to measure and quantify debonding strength at various loading rates is proposed. The method is experimentally verified using data obtained from a static test and a pulse-type dynamic test. The proposed method involves the cohesive zone model, which can uniquely be characterized with a few parameters. Since those parameters are difficult to be measured directly, indirect inference is deployed where the parameters are inferred by minimizing discrepancy of mechanical response of a numerical model and that of the experiments. The main finding suggests that the design is easy to be used for the debonding characterization and the numerical model can accurately predict the debonding for the both loading cases. The cohesive strength of the stress-wave case is significantly higher than that of the static case; meanwhile, the cohesive energy is twice larger.
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Abstrakt

In the dumps of metallurgical enterprises of Kazakhstan about 700 million tons of waste products are generated annually, and are polluting the atmosphere and the soil. The concentration of valuable components in waste products are no lower than in natural resources. The reserves of coal in the Ekibastuz basin are estimated to be more than a billion tons, and almost half of this is made up of ash. Every year, up to 30 million tons of ash-cinder waste is generated, which presents a serious threat to nature. Gallium and germanium concentrations in dumps are approximately 200 grams per ton, which is comparable to the content in coal before processing. The current research aims at creating a unit to obtain hydrogen-enriched water gas from Ekibastuz coal, with the production of zinc, gallium and germanium sublimates, copper-containing cast iron, slag wool and cast stone, through the joint processing of zinc-rich slag and ash-cinder wastes from thermal power plants. To achieve this, we used previous methods of extreme energy saving and a new method, the smelt layer with inversion phase. Experimental results from the “reactor inversion phase – rotary kiln” (RIPh) unit, which processed zinc-germanium contained slag, showed the potential to extract germanium from zinc sublimates, to reduce iron to the form of cupreous cast iron, and to obtain combustible gases and smelt suitable for slag-wool production. Calculations performed on the joint processing of Ekibastuz coal and zinc-rich slag using the proposed unit “reactor of inversion phase – rotary kiln – gas generator” showed it can obtain hydrogen-enriched water gas, along with the extraction of valuable components of primary raw material
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Abstrakt

The present article investigates the dynamic behavior of a fully assembled turbogenerator system influenced by misalignment. In the past, most of the researchers have neglected the foundation flexibility in the turbogenerator systems in their study, to overcome this modelling error a more realistic model of a turbogenerator system has been attempted by considering flexible shafts, flexible coupling, flexible bearings and flexible foundation. Equations of motion for fully assembled turbogenerator system including flexible foundations have been derived by using finite element method. The methodology developed based on least squares technique requires forced response information to quantify the bearing–coupling–foundation dynamic parameters of the system associated with different faults along with residual unbalances. The proposed methodology is tested for the various level of measurement noise and modelling error in the system parameters, i.e., 5% deviation in E (modulus of elasticity) and ρ (density), respectively, for robustness of the algorithm. In a practical sense, the condition analyzed in the present article relates to the identification of misalignment and other dynamic parameters viz. bearing and residual unbalance in a rotor integrated with flexible foundation
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Abstrakt

This paper presents the construction of adequate 3-D computer models for simulation research and analysis of dynamic aspects of caliper disc brakes, as well as of drum brakes, actuated by a short stroke electromagnet or a hydraulic thruster, when these brake types are used in the hoisting mechanism of cranes. The adequacy of the 3-D models has been confirmed by comparing their simulation results with results from an experiment and from classic computational models. The classic computational models, related to the study of main dynamic features of friction brakes, are layouts that are based on a number of assumptions, such as that the braking force instantly reaches its steady-state value, the clearance between the friction lining and the disc/drum is neglected, etc. These assumptions lead to a limitation of research options. The proposed 3-D computer models improve the research layouts by eliminating a number of the classic model assumptions. The improvements are related to the determination of the braking time, braking torque, normal force and other dynamic aspects of the brakes by performing simulations that take into account: the braking force as a function of time, the presence of clearance between the friction lining and the disc/drum, etc.
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Abstrakt

Pre-treatment techniques employed for exhaust emission control of compression ignition engines were found to reduce the emission levels by small percentage only, failing to meet the required emission regulations. Post-treatment technique including diesel particulate filtration, diesel oxidation catalysis and selective catalytic reduction is found to be an effective solution. While the fuel-based regeneration of diesel particulate filter leads to uncontrolled combustion affecting the durability of the filter. Development of an effective regeneration system is one of the major technical challenges faced by automotive industry for meeting emission norms. A composite regeneration system with the application of microwave energy is proposed in this paper. As an initial phase, a three-dimensional model of the system is developed and its flow analysis is carried out by considering the case of single channel flow. Simulation of the regeneration process is also done by developing a Simulink model. The results of simulation showed that an engine running continuously for a period of 24 hours would require three regenerations.
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Redakcja

Editor-in-Chief

Prof. Janusz Frączek, Warsaw University of Technology, Poland

 

Editorial Board

Prof. Krzysztof Arczewski, Warsaw University of Technology, Poland

Prof. Janusz T. Cieśliński, Gdańsk University of Technology, Poland

Prof. Antonio Delgado, LSTM University of Erlangen-Nuremberg, Germany

Prof. Peter Eberhard, University of Stuttgart, Germany

Prof. Jerzy Maciej Floryan, The University of Western Ontario, Canada

Prof. Tadeusz Ryszard Fodemski, Technical University of Lodz, Poland

Prof. Zenon Mróz, Institute of Fundamental Technological Research, Polish Academy of Sciences, Poland

Prof. Andrzej J. Nowak, Silesian University of Technology, Poland

Dr. Andrzej F. Nowakowski, The University of Sheffield, United Kingdom

Prof. Jerzy Sąsiadek, Carleton University, Canada

Prof. Jacek Szumbarski, Warsaw University of Technology, Poland

Prof. Tomasz Wiśniewski, Warsaw University of Technology, Poland

Prof. Günter Wozniak, Chemnitz University of Technology, Germany

 

Assistant to the Editor

Małgorzata Broszkiewicz, Warsaw University of Technology, Poland

 

Editorial Advisory Board

Prof. Alberto Carpinteri, Politecnico di Torino, Italy

Prof. Fernand Ellyin, University of Alberta, Canada

Prof. Feng Gao, Shanghai Jiao Tong University, P.R. China

Prof. Emmanuel E. Gdoutos, Democritus University of Thrace, Greece

Prof. Gregory Glinka, University of Waterloo, Ontario, Canada

Prof. Andrius Marcinkevicius, Vilnius Gedeminas Technical University, Lithuania

Prof. Manuel José Moreira De Freitas, Instituto Superior Tecnico, Portugal

Prof. Andrzej Neimitz, Kielce University of Technology, Poland

Prof. Masateru Ohnami, Ritsumeikan University, Kyoto, Japan

Prof. Thierry Palin-Luc, Arts et Métiers ParisTech, Institut Carnot Arts, France

Prof. Andre Pineau, Centre des Matériaux, Ecole des Mines de Paris, France

Prof. Narayanaswami Ranganathan, LMR, Ecole Polytechnique de l'Université de Tours, France

Prof. Jan Ryś, Cracow University of Technology, Poland

Prof. Adelia Sequeira, Technical University of Lisbon, Portugal,

Prof. Józef Szala, University of Technology and Life Sciences in Bydgoszcz, Poland

Prof. Edmund Wittbrodt, Gdańsk University of Technology, Poland

Prof. Jens Wittenburg, Karlsruhe Institute of Technology, Germany

Prof. Stanisław Wojciech, University of Bielsko-Biała, Poland

 

Language Editor

Lech Śliwa, Institute of Physiology and Pathology of Hearing, Warsaw, Poland

  

Kontakt

ARCHIVE OF MECHANICAL ENGINEERING

Editorial Office:

Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology

Nowowiejska 24, Room 132, 00-665 Warsaw, Poland

Phone:  (+48) 22 234 7448, fax: (+48) 22 628 25 87,

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https://www.editorialsystem.com/ame

www.journals.pan.pl/dlibra/journal/ame

 

Instrukcje dla autorów

About the Journal
Archive of Mechanical Engineering is an international journal publishing works of wide significance, originality and relevance in most branches of mechanical engineering. The journal is peer-reviewed and is published both in electronic and printed form. Archive of Mechanical Engineering publishes original papers which have not been previously published in other journal, and are not being prepared for publication elsewhere. The publisher will not be held legally responsible should there be any claims for compensation. The journal accepts papers in English.

Archive of Mechanical Engineering is an Open Access journal. The journal does not have article processing charges (APCs) nor article submission charges.

Original high quality papers on the following topics are preferred:

  • Mechanics of Solids and Structures,
  • Fluid Dynamics,
  • Thermodynamics, Heat Transfer and Combustion,
  • Machine Design,
  • Computational Methods in Mechanical Engineering,
  • Robotics, Automation and Control,
  • Mechatronics and Micro-mechanical Systems,
  • Aeronautics and Aerospace Engineering,
  • Heat and Power Engineering.

All submissions to the AME should be made electronically via Editorial System - an online submission and peer review system at: https://www.editorialsystem.com/ame

More detailed instructions for Authors can be found there.

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