TY - JOUR

T1 - Bonded and prestressed fatigue crack retarders based on Fe-SMA

AU - Wang, Wandong

AU - Guo, Xinlu

AU - Zhou, Wei

AU - Ma, Yu'e

AU - Motavalli, Masoud

AU - Ghafoori, Elyas

N1 - Funding Information: The financial funding from Innosuisse-Swiss Innovation Agency and re-fer AG with the project number 30060.1 IP-ENG is acknowledged. The authors would like to thank the technicians of the Empa Structural Engineering Lab for their assistance in performing the experiments. National Natural Science Foundation of China also supported the continuation of this project with the project number 52202509, which is sincerely acknowledged.

PY - 2024/7

Y1 - 2024/7

N2 - A bonded and prestressed retarder concept is proposed in this work. The shape memory effect of an iron-based shape memory alloy (Fe-SMA) has been exploited to realize a desirable self-prestressing mechanism, resulting in compressive stresses in the parent structure. The synergistic prestressing and added fail-safe features of bonded and prestressed Fe-SMA retarders desirably restrain the fatigue crack growth. The fatigue crack growth behaviour in metallic plates reinforced with bonded and prestressed retarders is experimentally studied in this work. A test campaign has been implemented to investigate the effects of prestressing, as well as the influence of the relative location between the Fe-SMA retarders and the initial crack tip on the crack growth behaviour and fatigue crack life extension. The experimental results show that the prestressing of retarders desirably extends the fatigue crack growth life. More extension in fatigue life can be achieved by positioning the bonded prestressed retarders from 40 to 20 mm before the initial crack tip, the desirable retardation due to beneficial compressive prestressing and added load path on the small crack is significant. The findings in this work imply that it is beneficial to proactively reinforce the fatigue-prone locations in metallic structures with bonded and prestressed Fe-SMA retarders in order to extend the service life.

AB - A bonded and prestressed retarder concept is proposed in this work. The shape memory effect of an iron-based shape memory alloy (Fe-SMA) has been exploited to realize a desirable self-prestressing mechanism, resulting in compressive stresses in the parent structure. The synergistic prestressing and added fail-safe features of bonded and prestressed Fe-SMA retarders desirably restrain the fatigue crack growth. The fatigue crack growth behaviour in metallic plates reinforced with bonded and prestressed retarders is experimentally studied in this work. A test campaign has been implemented to investigate the effects of prestressing, as well as the influence of the relative location between the Fe-SMA retarders and the initial crack tip on the crack growth behaviour and fatigue crack life extension. The experimental results show that the prestressing of retarders desirably extends the fatigue crack growth life. More extension in fatigue life can be achieved by positioning the bonded prestressed retarders from 40 to 20 mm before the initial crack tip, the desirable retardation due to beneficial compressive prestressing and added load path on the small crack is significant. The findings in this work imply that it is beneficial to proactively reinforce the fatigue-prone locations in metallic structures with bonded and prestressed Fe-SMA retarders in order to extend the service life.

KW - Adhesive bonding

KW - Fatigue crack retardation

KW - Fatigue life extension

KW - Prestressed retarders

KW - Self-prestressing

UR - http://www.scopus.com/inward/record.url?scp=85189031393&partnerID=8YFLogxK

U2 - 10.1016/j.ijfatigue.2024.108301

DO - 10.1016/j.ijfatigue.2024.108301

M3 - Article

AN - SCOPUS:85189031393

VL - 184

JO - International journal of fatigue

JF - International journal of fatigue

SN - 0142-1123

M1 - 108301

ER -