Significance and applicability of structural integrity assessment

Abstract

To avoid unexpected and frequent serious failures of objects and equipment in service, and save their structural integrity, proper experimental and theoretical analyses are required, that are supported by modeling and numerical analysis. Structural failures in service have been experienced and can not be neglected. The developed procedures, based on fracture mechanics, enable to predict behaviour of a crack in a fracture process and to evaluate the safety and reliability of a structure under the applied loading in an operating environment. Regarding the significance of structural integrity, objects are classified into three groups. In the first group are objects made of stone, not sensitive to cracking, as are the preserved monuments of the ancient era. The second group includes objects prone to fracture from cracks: in this case structural integrity assessment is a requirement in order to prevent failure. In the third group are modern engineering achievements as are very large buildings (e.g. Burj Khalifa), and nano-sized objects. They both require, involving new aspects, the consideration of functionality and reliability, in addition to safety. Several examples are presented here and discussed for each group.

Da bi se izbegli neočekivani i često ozbiljni otkazi u radu objekata i opreme i sačuvao integritet konstrukcija potrebne su odgovarajuće eksperimentalne i teorijske analize, podržane modeliranjem i numeričkom analizom. Mogućnost otkaza konstrukcije u radu se ne može zanemariti, jer se oni u praksi javljaju. Postupci, razvijeni na osnovu mehanike loma, omogućavaju da se predvidi ponašanje prsline u procesu loma i da se oceni sigurnost i pouzdanost konstrukcije pri opterećenju u radnim uslovima. Objekti su podeljeni u tri grupe s obzirom na značaj integriteta konstrukcije. U prvoj grupi su objekti, uglavnom izrađeni od kamena, koji nisu osetljivi na prsline, kao što su očuvani arheološki spomenici. Druga grupa uključuje konstrukcije sklone razvoju loma usled prslina: za njih se zahteva ocena integriteta da bi se sprečio otkaz. U trećoj grupi su nova tehnička dostignuća, kao što su velike građevine (na primer Burdž Kalifa) i objekti nano veličina. Zbog toga što se u oba slučaja unose novi aspekti, i objekti velikih i vrlo malih dimenzija zahtevaju da se, sem sigurnosti, razmotre funkcionalnost i pouzdanost. Za svaku grupu je nekoliko primera prikazano i diskutovano.