Proračun čvrstoće i stabilnosti sfernog spremnika za ukapljeni plin

undergraduate thesis

• Title (english): Strength and stability calculation of spherical LPG tank
• Author: Jana Bais
• Mentor: Ivica Skozrit (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Tema ovog završnog rada je kontrolni proračun čvrstoće i stabilnosti sfernog spremnika za
ukapljeni plin. Pojednostavljena konstrukcija spremnika sastoji se od sferne ljuske i stupova
koji ju podupiru. U analitičkom dijelu proveden je proračun čvrstoće sferne ljuske pod
djelovanjem unutarnjeg pretlaka i hidrostatskog tlaka ukapljenog plina. Izračunate su
vrijednosti i raspodjele membranskih sila, naprezanja te radijalnih pomaka središnje plohe
ljuske. Također je analizirano izvijanje nosivih stupova prema linearno elastičnoj teoriji
izvijanja, pri čemu su određene kritične sile izvijanja. Numerički proračun čvrstoće proveden
je u programskom paketu Abaqus®. Započet je ispitivanjem konvergencije rezultata modela
diskretiziranih različitim konačnim elemenata u usporedbi s rezultatima analitičkog proračuna.
Korišteni su jednodimenzijski element za analizu osnosimetričnih ljuski, osnosimetrični
pravokutni element i ljuskasti pravokutni element. Odabran je ljuskasti pravokutni konačni
element za kojeg je provedena dodatna verifikacija na stupovima. Za detaljniju analizu čvrstoće
analizirana je cijela konstrukcija spremnika, uključujući i stupove te ukrute na stupovima.
Kritična naprezanja očitana na modelu u programskom paketu Abaqus® uspoređuju se s
dopuštenim naprezanjima za finalni proračun čvrstoće. Na kraju je izvršena numerička analiza
izvijanja, najprije na jednostavnijem primjeru koji se slaže s analitičkim proračunom te zatim
na točnoj konstrukciji stupa, pri čemu je određena vrijednost kritične sile izvijanja.

Abstract (english)

The topic of this final paper is calculation of strength and stability of a spherical tank filled with
liquefied petroleum gas. Construction of the tank consists of a spherical shell supported by
columns. Analytical procedure contains strength calculation of spherical shell under the action
of internal overpressure and hydrostatic pressure of liquefied gas, which resulted in values and
distribution of membrane forces, stresses and radial displacements of the central surface of the
shell. Analytical procedure also contains buckling analysis of load-bearing columns according
to linear buckling analysis, which determined critical buckling forces. Numerical calculation of
strength was carried out using Abaqus® software package. It started by examining the
convergence of numerical calculation results on models discretized with different finite
elements in comparison with analytical calculation results. An axisymmetric shell element, an
axisymmetric quadrilateral element and a shell quadrilateral element were used. A shell
quadrilateral finite element was selected for which additional verification was performed on the
columns. For more detailed strength analysis, the entire construction of the tank was analyzed,
including the columns and the stiffeners on the columns. The critical stresses read on the model
in Abaqus® are compared with the allowed stress for the final strength calculation. At the end,
a numerical analysis of buckling was performed, first on a simpler example that agrees with the
model used in analytical calculation and then on the exact construction of the column, where
the value of the critical buckling force was determined.

• Keywords: analitički proračun; numerički proračun; sferni spremnik; Abaqus®; metoda konačnih elemenata; izvijanje
• Keywords (english): analytical calculation; numerical calculation; spherical tank; Abaqus®; finite elements method; buckling
• Language: croatian
• URN:NBN: urn:nbn:hr:235:466544
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-02-20 12:28:15