Seminar
MECHANICS OF MACHINES AND MECHANISMS - MODELS AND MATHEMATICAL METHODS

 

PROGRAM

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Plan rada Seminara Mehanika mašina i mehanizama - modeli i matematičke metode za DECEMBAR 2020.

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UTORAK, 08.12.2020. u 17:00, Live stream Beograd
Christos Vakouftsis, School of Mechanical Engineering, National Technical University of Athens (NTUA), Athens, Greece
THE EFFECT OF THERMAL HISTORY AND PRODUCTION PARAMETERS IN THE ACCURACY OF FUNCTIONAL COMPONENTS IN ADDITIVE MANUFACTURING
The evolving technology of Additive Manufacturing (AM) is posing novel challenges in manufacturing practice since nowadays functional, end-use components and assemblies are produced by commercially available AM equipment. In order to safeguard the functionality and the interchangeability of a part, the designer must clearly denote a set of geometrical product specifications (GPS) in the 3D model or in the engineering drawing. The goal of this lecture is to investigate the effect of thermal history and AM parameters in the accuracy of functional components and to address the issue of creating a novel methodology for designing these components in order to eliminate geometrical and dimensional deviations. For this purpose, the results of FE analysis for a popular AM test case will be presented in comparison with experimental measurements. Common AM defects as well as bad practices will also be discussed.

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UTORAK, 15.12.2020. u 17:00, Live stream Beograd
Victor Roda Casanova, Department of Mechanical Engineering and Construction, Universitat Jaume I, Spain
REVIEW OF APPROACHES FOR ANALYZING COUPLED MECHANICAL - THERMAL PROBLEM FOR PREDICTION THE OPERATING TEMPERATURE OF PLASTIC GEARS
Day after day we are observing that plastic gears are replacing metallic gears in a wide range of industrial applications, as they present many advantages over their metallic counterparts: they are easy and fast to manufacture, have a reduced cost, can be used without lubrication, offer a good resistance to corrosion and bring smooth and quiet operation, etc.
One of the main limitations of plastic gears is that their mechanical properties, and specially their load carrying capacity, are severely diminished by the increment of their working temperature. Unfortunately, these gears are subjected to a combination of effects (low thermal conductivity, elevated generation of frictional heat, etc.) that favour these temperature increments. For these reasons, an important step during the design stages of plastic gear transmissions is the determination of their working temperature.
Predicting the working temperature of plastic gears involves solving two problems of different nature. On the one hand, a mechanical problem in which a loaded tooth contact analysis of the gear transmission needs to be performed to determine the amount of heat that is generated during the meshing process (either by friction or by the hysteretic processes). On the other hand, a thermal problem in which a heat transfer analysis involving the generated heat and the typical heat transfer mechanisms (conduction, convection, and radiation) is conducted to determine the temperature of the gears.
These mechanical and thermal problems can be solved in a coupled or an uncoupled way, by analytical or numerical methods, resulting in a wide range of approaches that involve many variables and complexities. In this lecture, these approaches will be reviewed to provide the attendants a clear image of the alternatives that are available for this process, as well as the main parameters that guide them.

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Obavezno je nošenje maski i održavanje distance. Broj prisutnih na predavanju ograničen na najviše 10 (uključujući i predavača).

Seminar Mehanika mašina i mehanizama - modeli i matematičke metode započeo je sa radom u junu 2018.god. Seminar se održava do dva puta mesečno, utorkom u periodu od 17.00 - 19.00 u Matematičkom institutu SANU.

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