Details
| Original language | English |
|---|---|
| Pages (from-to) | 119-134 |
| Number of pages | 16 |
| Journal | Composite structures |
| Volume | 178 |
| Publication status | Published - 29 Jun 2017 |
| Externally published | Yes |
Abstract
Numerous studies in the literature have shown that the strengthening of steel members using carbon fiber reinforced polymer (CFRP) composites can significantly extend the fatigue life of these structures. However, not enough attention has been focused on the potential of prestressed CFRP reinforcements for fatigue crack arrest in such members. In the current study, a simple analytical model is proposed to calculate the required prestressing level in the CFRP reinforcements in order to arrest the propagation of an existing fatigue crack in tensile steel members. Furthermore, a novel mechanical unbonded system is developed to anchor the high prestressing forces in CFRP reinforcements to the steel substrate using friction. A set of fatigue tests are performed on unstrengthened and strengthened precracked steel plates to verify the proposed model. The experimental results of the current study showed that the application of nonprestressed ultra-high modulus CFRP plates as externally bonded reinforcements can increase the fatigue life of precracked steel plates by a factor of 4.3. However, fatigue crack arrest is only possible when prestressed CFRPs of a certain prestressing level are used. Based on the analytical, numerical, and experimental results of the current study, it can be concluded that existing fatigue cracks in tensile steel members can be arrested using the proposed prestressed unbonded reinforcement system with the initial prestressing level calculated using the proposed model. In addition, some design recommendations are provided for fatigue crack arrest in practical cases.
Keywords
- Carbon fiber reinforced polymer (CFRP), Crack arrest, Fatigue strengthening, Prestressed unbonded reinforcement (PUR), Steel structures
ASJC Scopus subject areas
- Materials Science(all)
- Ceramics and Composites
- Engineering(all)
- Civil and Structural Engineering
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In: Composite structures, Vol. 178, 29.06.2017, p. 119-134.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Mode I fatigue crack arrest in tensile steel members using prestressed CFRP plates
AU - Hosseini, Ardalan
AU - Ghafoori, Elyas
AU - Motavalli, Masoud
AU - Nussbaumer, Alain
AU - Zhao, Xiao Ling
N1 - Funding Information: The authors gratefully acknowledge the financial support provided by the Swiss National Science Foundation (Project No: 5211.00892.100.01) and the Australian Research Council (ARC) Linkage Grant (LP140100543). The authors also would like to thank the technicians of the Structural Engineering Research Laboratory, Mechanical Systems Engineering Laboratory, and the Central Workshop of Empa for their exceptional cooperation in manufacturing the mechanical parts and performing the experiments. Finally, support from S&P Clever Reinforcement Company AG, Switzerland, by providing the materials for the current study is acknowledged.
PY - 2017/6/29
Y1 - 2017/6/29
N2 - Numerous studies in the literature have shown that the strengthening of steel members using carbon fiber reinforced polymer (CFRP) composites can significantly extend the fatigue life of these structures. However, not enough attention has been focused on the potential of prestressed CFRP reinforcements for fatigue crack arrest in such members. In the current study, a simple analytical model is proposed to calculate the required prestressing level in the CFRP reinforcements in order to arrest the propagation of an existing fatigue crack in tensile steel members. Furthermore, a novel mechanical unbonded system is developed to anchor the high prestressing forces in CFRP reinforcements to the steel substrate using friction. A set of fatigue tests are performed on unstrengthened and strengthened precracked steel plates to verify the proposed model. The experimental results of the current study showed that the application of nonprestressed ultra-high modulus CFRP plates as externally bonded reinforcements can increase the fatigue life of precracked steel plates by a factor of 4.3. However, fatigue crack arrest is only possible when prestressed CFRPs of a certain prestressing level are used. Based on the analytical, numerical, and experimental results of the current study, it can be concluded that existing fatigue cracks in tensile steel members can be arrested using the proposed prestressed unbonded reinforcement system with the initial prestressing level calculated using the proposed model. In addition, some design recommendations are provided for fatigue crack arrest in practical cases.
AB - Numerous studies in the literature have shown that the strengthening of steel members using carbon fiber reinforced polymer (CFRP) composites can significantly extend the fatigue life of these structures. However, not enough attention has been focused on the potential of prestressed CFRP reinforcements for fatigue crack arrest in such members. In the current study, a simple analytical model is proposed to calculate the required prestressing level in the CFRP reinforcements in order to arrest the propagation of an existing fatigue crack in tensile steel members. Furthermore, a novel mechanical unbonded system is developed to anchor the high prestressing forces in CFRP reinforcements to the steel substrate using friction. A set of fatigue tests are performed on unstrengthened and strengthened precracked steel plates to verify the proposed model. The experimental results of the current study showed that the application of nonprestressed ultra-high modulus CFRP plates as externally bonded reinforcements can increase the fatigue life of precracked steel plates by a factor of 4.3. However, fatigue crack arrest is only possible when prestressed CFRPs of a certain prestressing level are used. Based on the analytical, numerical, and experimental results of the current study, it can be concluded that existing fatigue cracks in tensile steel members can be arrested using the proposed prestressed unbonded reinforcement system with the initial prestressing level calculated using the proposed model. In addition, some design recommendations are provided for fatigue crack arrest in practical cases.
KW - Carbon fiber reinforced polymer (CFRP)
KW - Crack arrest
KW - Fatigue strengthening
KW - Prestressed unbonded reinforcement (PUR)
KW - Steel structures
UR - http://www.scopus.com/inward/record.url?scp=85023647288&partnerID=8YFLogxK
U2 - 10.1016/j.compstruct.2017.06.056
DO - 10.1016/j.compstruct.2017.06.056
M3 - Article
AN - SCOPUS:85023647288
VL - 178
SP - 119
EP - 134
JO - Composite structures
JF - Composite structures
SN - 0263-8223
ER -