Numerička analiza kućišta elektromotora namijenjenog za rad u eksplozivnoj okolini

master's thesis

• Title (english): Numerical analysis of electromotor housing intended for operation in explosive environment
• Author: Tomislav Mihaljević
• Mentor: Ivica Skozrit (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2019-03-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Tema ovog rada je numerička analiza odabranog tipa kućišta elektromotora, iz serije elektromotora za protueksplozijsku zaštitu, podvrgnutom statičkom ispitnom tlaku. Na početku rada dan je kratki uvod u tematiku protueksplozijske zaštite te je dana klasifikacija prostora, opreme i medija u protueksplozijskoj zaštiti. Nastavno na to su navedeni osnovni tipovi zaštite, odnosno zaštitne mjere te je pobliže opisan princip zaštite oklapanjem koji se koristi kod odabranog kućišta elektromotora. Zatim su opisana karakteristična ispitivanja opreme u zaštiti oklapanjem (“d” zaštiti). Numerička analiza kućišta temelji se na metodi konačnih elemenata. U nastavku rada ukratko je opisana metoda konačnih elemenata i osnovni elementi koje će se koristiti za analizu. Zatim je provedena verifikacija spomentih elemenata kako bi se utvrdilo da li su pogodni za ovaj tip numeričke analize. Verfikacija je provedena na primjeru tankostjenog cilindra te savijanja grede T-poprečnog presjeka. U poglavlju o verifikaciji prvo su navedeni osnovni analitički izrazi za izračun naprezanja i pomaka u odabranim primjerima, a zatim je izvršena i numerička analiza te je prikazana konvergencija rješenja i usporedba sa analitičkim rješenjima. U nastavku rada provedene su numeričke analize pojedinih segmenata kućišta kako bi se prije konačne analize utvrdila potencijalna kritična mjesta. Tlačno ispitivanje kućišta simulirano je trima tipovima rubnih uvjeta i opterećenja te je na samom kraju rada za sva tri tipa rubnih uvjeta provedena numerička analiza kompletnog modela kućišta. Prikazana su kritična mjesta na kućištu te su provedene analize pri različitim tlakovima kako bi se utvrdilo maksimalni tlak koje kućište može podnijeti bez pojave pukotina.

Abstract (english)

The topic of this thesis is the numerical analysis of the housing of electric motor designed for work in explosive atmosphere. Such housing is subjected to static pressure during testing. In the beginning of paper a brief introduction to the field of explosive protection is given, alongside with space, gear and medium classifications. After that, basic types of explosive protection are listed and a more thorough description of flame-proof protection is given as it is the applied type of protection in the design of selected housing. Following that are descriptions of basic types of tests that are conducted within flame-proof protection ("d" type of protection). Numerical analysis is based on the finite element method. In following sections aforementioned method is described, alongside with basic element types that are planned to be used for analysis. Verification of such elements is then conducted to determine if those elements are suitable for numerical analysis. Verification is carried out on the example of a closed, thin walled, cylinder submitted to internal pressure and T-cross section beam submitted to bending pressure. Analytical expressions for calculation of stresses and displacements were given. Numerical analysis was then executed and obtained results were compared to analytical results and the convergence of results was shown. In the following pages numerical analysis of individual housing segments was carried out to identify critical spots on the construction before conducting final analysis. Pressure test of the housing is simulated by three types of boundary conditions and load types. For each of them numerical analysis of complete housing was carried out and after the stresses on critical spots were obtained the analysis was executed with two more different internal pressures values to show the maximum pressure that housing can be subjected to without the appearance of cracks.

• Keywords: elektromotor; kućište; protueksplozijska zaštita; tlačno ispitivanje; numerička analiza; metoda konačnih elemenata
• Keywords (english): electric motor; explosive protection; pressure test; numerical analysis; finite element method
• Language: croatian
• URN:NBN: urn:nbn:hr:235:344774
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-23 00:42:31