Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates

Publikation: Beitrag in Buch/Bericht/Sammelwerk/KonferenzbandAufsatz in KonferenzbandForschungPeer-Review

Autoren

  • Elyas Ghafoori
  • Masoud Motavalli
  • Alain Nussbaumer
  • Andrin Herwig
  • Gary S. Prinz
  • Mario Fontana
  • Xiao Ling Zhao

Externe Organisationen

  • Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA)
  • ETH Zürich
  • Eidgenössische Technische Hochschule Lausanne (ETHL)
  • University of Arkansas
Forschungs-netzwerk anzeigen

Details

OriginalspracheEnglisch
Titel des SammelwerksProceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014
Herausgeber/-innenRaafat El-Hacha
ISBN (elektronisch)9781771363082
PublikationsstatusVeröffentlicht - 2014
Extern publiziertJa
Veranstaltung7th International Conference on FRP Composites in Civil Engineering, CICE 2014 - Vancouver, Kanada
Dauer: 20 Aug. 201422 Aug. 2014

Publikationsreihe

NameProceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014

Abstract

The majority of fatigue strengthening studies using CFRP materials focus on reducing propagation rates of existing cracks or flaws, ignoring the crack initiation stage. However, many existing metallic bridge members do not contain existing cracks, but rather are nearing their design fatigue life wherein crack initiation is approaching. Limited research exists on the prevention of crack initiation using CFRP materials. In this paper, the use of CFRP plates with tuned degrees of pre-stress are investigated, to extend steel bridge member fatigue life (prevent crack initiation). The modified Goodman constant life diagram (CLD) is used to determine the safe regime of constant amplitude loading required to extend an existing member into the infinite fatigue-life zone. Following, the minimum level of CFRP pre-stress is determined to achieve this safe loading regime, and experimental testing of four metallic beams containing pre-stress CFRP retrofits validate the proposed method. Experimental results show that strengthening using pre-stressed CFRP plates can shift the working stresses from a finite fatigue-life zone to an infinite fatigue-life zone indefinitely preventing crack initiation.

ASJC Scopus Sachgebiete

Zitieren

Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates. / Ghafoori, Elyas; Motavalli, Masoud; Nussbaumer, Alain et al.
Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. Hrsg. / Raafat El-Hacha. 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).

Publikation: Beitrag in Buch/Bericht/Sammelwerk/KonferenzbandAufsatz in KonferenzbandForschungPeer-Review

Ghafoori, E, Motavalli, M, Nussbaumer, A, Herwig, A, Prinz, GS, Fontana, M & Zhao, XL 2014, Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates. in R El-Hacha (Hrsg.), Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014, 7th International Conference on FRP Composites in Civil Engineering, CICE 2014, Vancouver, Kanada, 20 Aug. 2014.
Ghafoori, E., Motavalli, M., Nussbaumer, A., Herwig, A., Prinz, G. S., Fontana, M., & Zhao, X. L. (2014). Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates. In R. El-Hacha (Hrsg.), Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014 (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).
Ghafoori E, Motavalli M, Nussbaumer A, Herwig A, Prinz GS, Fontana M et al. Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates. in El-Hacha R, Hrsg., Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).
Ghafoori, Elyas ; Motavalli, Masoud ; Nussbaumer, Alain et al. / Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates. Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. Hrsg. / Raafat El-Hacha. 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).
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title = "Constant life diagrams to prevent fatigue crack initiation in metallic beams using CFRP plates",
abstract = "The majority of fatigue strengthening studies using CFRP materials focus on reducing propagation rates of existing cracks or flaws, ignoring the crack initiation stage. However, many existing metallic bridge members do not contain existing cracks, but rather are nearing their design fatigue life wherein crack initiation is approaching. Limited research exists on the prevention of crack initiation using CFRP materials. In this paper, the use of CFRP plates with tuned degrees of pre-stress are investigated, to extend steel bridge member fatigue life (prevent crack initiation). The modified Goodman constant life diagram (CLD) is used to determine the safe regime of constant amplitude loading required to extend an existing member into the infinite fatigue-life zone. Following, the minimum level of CFRP pre-stress is determined to achieve this safe loading regime, and experimental testing of four metallic beams containing pre-stress CFRP retrofits validate the proposed method. Experimental results show that strengthening using pre-stressed CFRP plates can shift the working stresses from a finite fatigue-life zone to an infinite fatigue-life zone indefinitely preventing crack initiation.",
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AU - Ghafoori, Elyas

AU - Motavalli, Masoud

AU - Nussbaumer, Alain

AU - Herwig, Andrin

AU - Prinz, Gary S.

AU - Fontana, Mario

AU - Zhao, Xiao Ling

PY - 2014

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N2 - The majority of fatigue strengthening studies using CFRP materials focus on reducing propagation rates of existing cracks or flaws, ignoring the crack initiation stage. However, many existing metallic bridge members do not contain existing cracks, but rather are nearing their design fatigue life wherein crack initiation is approaching. Limited research exists on the prevention of crack initiation using CFRP materials. In this paper, the use of CFRP plates with tuned degrees of pre-stress are investigated, to extend steel bridge member fatigue life (prevent crack initiation). The modified Goodman constant life diagram (CLD) is used to determine the safe regime of constant amplitude loading required to extend an existing member into the infinite fatigue-life zone. Following, the minimum level of CFRP pre-stress is determined to achieve this safe loading regime, and experimental testing of four metallic beams containing pre-stress CFRP retrofits validate the proposed method. Experimental results show that strengthening using pre-stressed CFRP plates can shift the working stresses from a finite fatigue-life zone to an infinite fatigue-life zone indefinitely preventing crack initiation.

AB - The majority of fatigue strengthening studies using CFRP materials focus on reducing propagation rates of existing cracks or flaws, ignoring the crack initiation stage. However, many existing metallic bridge members do not contain existing cracks, but rather are nearing their design fatigue life wherein crack initiation is approaching. Limited research exists on the prevention of crack initiation using CFRP materials. In this paper, the use of CFRP plates with tuned degrees of pre-stress are investigated, to extend steel bridge member fatigue life (prevent crack initiation). The modified Goodman constant life diagram (CLD) is used to determine the safe regime of constant amplitude loading required to extend an existing member into the infinite fatigue-life zone. Following, the minimum level of CFRP pre-stress is determined to achieve this safe loading regime, and experimental testing of four metallic beams containing pre-stress CFRP retrofits validate the proposed method. Experimental results show that strengthening using pre-stressed CFRP plates can shift the working stresses from a finite fatigue-life zone to an infinite fatigue-life zone indefinitely preventing crack initiation.

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