Simulacija rasta kolinearnih zamornih pukotina u tankim pločama

master's thesis

• Title (english): Simulation of collinear fatigue crack growth in thin plates
• Author: Vlatko Jakupčić
• Mentor: Željko Božić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-01-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

U ovom su radu predstavljene neke od uobičajenih metoda analize napredovanja zamornih pukotina bazirane na principima mehanike loma prilikom cikličkog opterećenja. Također je i dan općeniti pregled mehanike loma, kao i njena primjena na propagaciju pukotina. Iz literature su dani eksperimentalni rezultati rasta zamornih pukotina za uzorak ploče sa središnjom pukotinom i tri pukotine u nizu. Primjenjujući postupak numeričke integracije Parisove jednadžbe, simuliran je životni vijek središnje te triju kolinearnih zamornih pukotina u nizu za promatrani uzorak tanke ploče, pri čemu je uzeta u obzir njihova međusobna interakcija. Procedura je provedena uz pomoć numeričkog programa MATLAB. Koeficijenti intenzivnosti naprezanja su izračunati primjenom metode konačnih elemenata, gdje se područje oko vrha pukotine modelira mrežom singularnim konačnim elementima. Dobivene rezultate naposljetku uspoređujemo s eksperimentalnim podacima rasta središnje i kolinearnih pukotina u pločama opterećenim cikličkim vlačnim naprezanjima preuzetim iz literature. Dodatno je prikazana ovisnost između vrijednosti koeficijenata naprezanja u odnosu na duljine pukotina.

Abstract (english)

In this work some of the common methods that are used for fatigue crack propagation analysis based on fracture mechanics principles are introduced. Also, an overview of fracture mechanics, same as its application on crack propagation is given. For a plate specimen containing one central crack, and also an array of three cracks, experimental results of fatigue crack grow are given from the literature. By applying the procedure of numerical integration of Paris equation, fatigue life for a central crack and for three collinear cracks in a thin plate specimen simulated for thin-plate specimen, where the interaction of multiple propagating crack tips is taken into account. Procedure is implemented by means of MATLAB package. Stress intensity factors are calculated by usage of finite element method, where the crack tip region was meshed by using singular elements. Eventually, simulatin results are compared with experimental results taken from the literature. In addition, dependence between stress intensity factor values with respect to various crack lengths are also presented.

• Keywords: napredovanje zamornih pukotina; koeficijent intenzivnosti naprezanja; cikličko opterećenje; višestruke pukotine
• Keywords (english): fatigue crack propagation; stress intensity factor; cyclic loading; multiple cracks
• Language: croatian
• URN:NBN: urn:nbn:hr:235:175140
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering, Mechatronics and Robotics, Autonomous Systems; Course: Engineering Modelling and Computer Simulation; 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: Embargoed access; Embargo expiration date: 2028-01-25
• Created on: 2023-01-21 15:04:01