Određivanje korekcijskog faktora uslijed deformiranja dvoosne horizontalne vlačne kidalice

master's thesis

• Title (english): Determination of the correction factor due to the deformation of the horizontal biaxial tensile testing machine
• Author: Luka Labar
• Mentor: Lana Virag (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-07-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Prilikom razvlačenja ispitnog uzorka na dvoosnoj horizontalnoj kidalici, zbog reakcijske sile dolazi i do deformacije same konstrukcije kidalice. To znači da pomak aktuatora preko kojeg se razvlači epruveta ne uzrokuje samo deformaciju epruvete nego i deformaciju konstrukcije. Iako je ta deformacija mala, ne smije se zanemariti jer bi to moglo imati utjecaja na provođenje eksperimenata i na određivanje svojstava materijala ispitnog uzorka. Preko korekcijskog faktora bi se pomak aktuatora automatski korigirao tako da ostvareno rastezanje ispitnog uzorka bude jednako zadanom. Cilj ovog rada je stoga određivanje potrebne korekcije metodom konačnih elemenata (MKE), primjenom programskog paketa Abaqus® na geometriji kidalice sa spuštenim čeljustima te na geometriji sa podignutim čeljustima. Prije same numeričke analize, uvodnim dijelom rada prikazane su osnove o materijalima i njihovom ispitivanju. Drugim poglavljem prikazane su osnove dvoosnog vlačnog ispitivanja, vrste prihvata uzoraka, način provedbe eksperimenta te je izveden konstitutivni model. U trećem poglavlju ukratko je opisan princip rada dvoosne horizontalne kidalice te ideja samog rada. Četvrto poglavlje prikazuje osnove metode konačnih elemenata te programskog paketa Abaqus®. Petim poglavljem opisan je postupak modeliranja u programskom paketu Abaqus® te su prikazani rezultati analiza za obje geometrije na modelima cijele konstrukcije te na modelima bez postolja. U šestom poglavlju određene su korekcije za obje geometrije u obliku korekcijskih dijagrama i jednadžbe pravca koje opisuje pravce na dijagramima.

Abstract (english)

During the tensile testing of the specimen on a biaxial horizontal tensile tester, there is deformation not only in the specimen itself but also in the structure of the tensile tester due to the reaction force. This means that the displacement of the actuator used to stretch the specimen causes deformation not only in the specimen but also in the overall structure. Although this deformation is small, it should not be neglected as it could impact the execution of experiments and the determination of material properties of the test specimen. By using a correction factor, the displacement of the actuator can be automatically adjusted to ensure that the achieved strain in the test specimen is equal to the desired value. The objective of this paper is to determine the necessary correction using the finite element method (FEM), with the application of the Abaqus® software, on the geometry of the tensile tester with lowered clamps and on the geometry with raised clamps. Before the numerical analysis itself, the fundamentals of materials and their testing are presented in the introductory chapter of the paper. In the second chapter, the basics of biaxial tensile testing, types of specimen grips, experimental procedures and the constitutive model are presented. The third chapter provides a brief description of the working principle of the biaxial horizontal tensile tester and the concept of the study. The fourth chapter outlines the basics of the finite element method and the Abaqus® software. The modeling procedure in the Abaqus® software is described in the fifth chapter, and the analysis results for both geometries are presented, considering complete structural models as well as models without legs. In the sixth chapter, corrections for both geometries are determined in the form of correction diagrams and the equation of the line that describes the lines on the diagrams.

• Keywords: Deformacija ispitnog uređaja; dvoosna horizontalna kidalica; korekcijski dijagram; metoda konačnih elemenata (MKE)
• Keywords (english): Biaxial horizontal tensile tester; correction diagram; deformation of the testing device; finite element method (FEM)
• Language: croatian
• URN:NBN: urn:nbn:hr:235:732918
• 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: 2023-07-06 10:11:18