CONCENTRATION IN WELDS DUE TO THE PRESENCE OF PORES

Ivan Kolarov

Scientific paper ID 2011 : 2020/3

CONCENTRATION IN WELDS DUE TO THE PRESENCE OF PORES

Ivan Kolarov

The possibility of pore formation in the weld is a known problem, which is discussed in a number of regulations.

The value of the stress concentration coefficient from the presence of one or more pores is studied in the work. The pores are created with an ideal and real shape in 3D CAD module and the stresses are measured in areas close to the concentrations. The maximum concentration (9.6) is obtained for a hexagonal prism-shaped pore at the intersection of three edges with a radius of curvature of 0.01 mm. Maximum concentrations (6.1) were recorded in the edges formed by the walls of the prism, and a value of 2 was obtained in the far zone of these local peaks. For a pore with an irregular rotational shape, 2.24 was obtained, for a pore with a spherical shape – 1.8.

The accuracy of the virtual experiment was evaluated by comparing the results obtained for a classical concentrator with known value.

The obtained values are indicative and show a wide range of concentrations values as a result of the actual shape of the pores in the seam.

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Концентратор на напрежение от пори с идеална и реална форма в заваръчен шев Pore stress concentrator with perfect and real shape in the weldIvan Kolarov

BIBLIOGRAPHY

[1] Welding of Pipelines and Related Facilities. API Standard 1104 : 2005

[2] BDS ISO 5817:2014. Zavaryavane. Zavaryavane chrez stopyavane na saedineniya ot stomana, nikel, titan i tehnite splavi (s izklyuchenie na lachevo zavaryavane). Niva na kachestvo spored nesavarshenstvata.
( [2] БДС ISO 5817:2014. Заваряване. Заваряване чрез стопяване на съединения от стомана, никел, титан и техните сплави (с изключение на лъчево заваряване). Нива на качество според несъвършенствата. )

[3] Kolarov I., P. Tashev. Ultrazvukovo izsledvane na nano-modifitsirani s Tin sloeve, polucheni chrez navaryavane s traben samozashtiten tel. Natsionalna nauchno-tehnicheska konferentsiya „Akustika 2015” str. 106 – 109. Sofiya. (ISSN 1312-4897)
( [3] Коларов И., П. Ташев. Ултразвуково изследване на нано-модифицирани с Tin слоеве, получени чрез наваряване с тръбен самозащитен тел. Национална научно-техническа конференция „Акустика 2015” стр. 106 – 109. София. (ISSN 1312-4897) )

[4] Plamen Tachev, Hristo Kondov, Мara Kandeva, Elisaveta Tasheva “ Wear-resistance study of nano-modified coatings by TIG surfacing process”, Belgrade, Serbia, 13 – 15 May 2015

[5] Mechanical Engineering. Shigley’s Mechanical Engineering Design, Eighth Edition Budynas−Nisbett. ISBN: 0−390−76487−6

[6] https://www.fracturemechanics.org/hole.html