@phdthesis{
author = "Jeremić, Lazar",
year = "2020",
abstract = "Predmet ove doktorske disertacije je istraživanje ponašanja zavarenih konstrukcija sa smanjenim stepenom sigurnosti prema krtom lomu i otpornost na prsline u cilju ocene njenog integriteta i veka. U tom slučaju posebna pažnja se posvećuje mestima koncentracije napona, jer se krti lomovi ovih konstrukcija po pravilu događaju upravo na takvim mestima. Radi detaljnog proučavanja nakstanka i rasta prsline, neophodna je primena principa mehanike loma, jer klasični pristup konstruisanju (projektovanju) preko faktora koncentracije napona i čvrstoće u tom slučaju nije dovoljan. Primenom parametra mehanike loma, kao što je faktor inteziteta napona, čiji opseg definiše brzinu rasta prline, a čija kritična veličina (žilavost loma) određuje kritičnu dužinu prsline. Time se obezbeđuje pouzdana procena integriteta konstrukcije (ako se dokaže da je faktor intenziteta napona manji od žilavosti loma), odnosno procena veka konstrukcije (primenom zakona mehanike loma na izračuvavanje krritičnih parametara za poznatu ili pretpostavljenu početnu dužinu prsline, njenu kritičnu vrednost, kao i izračunati opseg faktora intenzitata napona). Konzervativni pristup u svim koracima ove procedure obezbeđuje pouzdanu eksploataciju konstrukcije sa smanjenim stepenom sigurnosti., The subject of this doctoral dissertation is the research of the behavior of welded structures with a reduced degree of safety on brittle fracture and crack resistance in order to assess its integrity and age. In this case, special attention is paid to the stress concentration points, since the fractures of these structures tend to occur exactly in such places. For the detailed study of the crack and growth of the crack, it is necessary to apply the principle of fracture mechanics, since the classical approach to design (design) through the factor of stress concentration and strength is not sufficient in that case. Using the fracture mechanics parameter, such as the voltage intensity factor, whose range defines the rate of crack growth, and whose critical size (fracture toughness) determines the critical crack length. This ensures a reliable assessment of the integrity of the structure (if it is proven that the stress intensity factor is less than the tensile strength of the fracture), or the assessment of the century of construction (by applying laws of fracture mechanics to calculate critical parameters for known or assumed initial crack length, its critical value, as well as calculate the range voltage intensities factor). A conservative approach in all steps of this procedure ensures reliable exploitation of a structure with a reduced degree of safety",
publisher = "Univerzitet u Beogradu, Mašinski fakultet",
title = "Procena integriteta zavarenih konstrukcija projektovanih sa smanjenim stepenom sigurnosti, Integrity assessment of welded structures designed with reduced safety",
url = "https://hdl.handle.net/21.15107/rcub_nardus_18071"
}
