The effect of polymer pipe weld geometry on creep lifetime

The effect of polymer pipe weld geometry on creep lifetime

Článek recenzovaný mimo WoS a Scopus

In the case of large diameter HDPE and polypropylene (PP) pipes the most usual joint is butt weld. Usually, a good quality of a butt welded joint means that strength of the joint should be about the same as valid for the basic pipe material. In reality geometry, morphology and material structure of welded joints on micro- and macro-level are more complicated in comparison with the base homogeneous pipe material. The formation of weld structure is highly dependent on both thermal history and corresponding stress state. The geometry of the weld and change of the material properties inside the weld can change failure resistance of the pipe system. The primary objective of this work is to estimate the influence of weld deposit geometry on the failure assessment of the welded polymer pipes under creep loading. To this aim an overlay of the material near the weld is modeled as a notch and corresponding stress distribution and its triaxiality is analyzed. The calculations are performed for real geometry of the butt weld and can help estimate lifetime of the structures considered.

In the case of large diameter HDPE and polypropylene (PP) pipes the most usual joint is butt weld. Usually, a good quality of a butt welded joint means that strength of the joint should be about the same as valid for the basic pipe material. In reality geometry, morphology and material structure of welded joints on micro- and macro-level are more complicated in comparison with the base homogeneous pipe material. The formation of weld structure is highly dependent on both thermal history and corresponding stress state. The geometry of the weld and change of the material properties inside the weld can change failure resistance of the pipe system. The primary objective of this work is to estimate the influence of weld deposit geometry on the failure assessment of the welded polymer pipes under creep loading. To this aim an overlay of the material near the weld is modeled as a notch and corresponding stress distribution and its triaxiality is analyzed. The calculations are performed for real geometry of the butt weld and can help estimate lifetime of the structures considered.

creep, stress concentration factor, lifetime, triaxiality

creep, stress concentration factor, lifetime, triaxiality

ŠEVČÍK, M.; HUTAŘ, P.; NÁHLÍK, L.; KNÉSL, Z.

2011

05.01.2011

Trans Tech Publications

Switzerland

1013-9826

Key Engineering Materials (print)

465

-

Švýcarská konfederace

175

178

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