22 KB299 KB21 KB200020242006Božić, ŽeljkoSemenski, DamirWolf, Hinkoštevilka:4letnik:406 stranistr. 123-128ISSN:1580-2949COBISSID:561066URN:URN:NBN:SI:doc-08LPS5JIenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijekompozitipreiskava materialarazpokeA crack growth analysis in critical structural components|The supervising and health monitoring of structures is a new field that has been of increasing importance with regard to control durability, stability and safety as well as for estimating the life span of the structure. Crack growth is interesting for the proper evaluation of the reliability of structural parts. Different methods are used to record the actual situation in order to get reliable information about the on-site structure and structural elements. The experimental techniques in fracture mechanics are employed for determining the stress-intensity factors (SIFs) of the cracks in deformed structures. A procedure for the simulation of crack propagation for multiple cracks was introduced and SIFs have been calculated by using the finite-element method. The crack growth of a single crack or a periodic array of cracks initiated at the stiffeners in a stiffened panel has been investigated. The optical method of caustics is established for the application to mechanically isotropic materials through the process of SIF's evaluation and has advantageously improved applications with fiber-reinforced composites. Using high-speed photography and optical interferometric methods, we analyzed the phenomena of the dynamic failure process in composites and high-speed delamination. Valuable information gathered by the analysis of critical structural components should be important for making decisions about the structural repairing or the halting of a plant's production. Significant examples are the analysis of structures of the deck of a ship, the jacket of a gas and oil platform and the aeolian vibrations in electrical transmission lines that can cause severe damage or even the breakdown of the conductor due to material fatigueNadzor in ugotavljanje integritete konstrukcij je aktivnost z naraščujočim pomenom zaradi kontrole trajnosti, stabilnosti in varnosti ter ugotavljanja preostale trajnostne dobe struktur. Raziskave rasti razpok so potrebne zaradi ocene zanesljivosti delov struktur. V uporabi so različne metode za ugotavljanje stanja. Eksperimentalne metode mehanike loma se uporabljajo za določanje faktorja intenzitete napetosti (SIFs) za razpoke v obremenjenih strukturah. Razvita je bila procedura za simulacijo propagacije razpoke v primeru več razpok in izračunana je bila SIFs uporabo metode končnih elementov. Raziskana je bila rast ene ali večrazpok, ki so nastale ob ojačitvah v ojačanem panelu. Optična metoda svetlobnih odsevov je bila razvita za uporabo pri mehansko izotropnih materialih z določitvijo SIFs in prilagojena za uporabo pri vlaknatih kompozitih. Z uporabo fotografije z veliko hitrostjo in optično interferometrijo je bil analiziran pojav dinamičnega zloma kompozitov in hitre delaminacije. Podatki, zbrani z analizo kritičnih komponent struktur, so temeljnega pomena pri odločitvah o popravilih ali ustavitvah proizvodnih naprav. Prikazani so primeri analize krova ladijske strukture, armatur plinskih in naftnih ploščadi ter vibracije zaradi vetra pri električnih daljnovodih, ki lahko povzročijo resno škodo ali celo zlom zaradi utrujenosti materialaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije