{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T12:15:39Z","timestamp":1785413739501,"version":"3.56.0"},"reference-count":28,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T00:00:00Z","timestamp":1783296000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52378125"],"award-info":[{"award-number":["52378125"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["52378125"],"award-info":[{"award-number":["52378125"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>To investigate the influence of porosity defects and the strengthening effect of bonded iron-based shape memory alloy (Fe-SMA) plates, fatigue tests were conducted on defect-free, porosity-containing, and Fe-SMA-strengthened U-rib butt-welded specimens. A numerical model considering porosity defects and the bonded Fe-SMA plate was also established and validated against the experimental results. The results show that porosity defects significantly increased the local stress level near the crack. Under a load of 60 kN, the stress at the section 2 mm from the crack edge increased from 98 MPa to 139.5 MPa. Meanwhile, the fatigue life decreased from 260 \u00d7 104 cycles to 127 \u00d7 104 cycles. After Fe-SMA strengthening, the stress decreased to 75.59 MPa, and the fatigue life increased to 326 \u00d7 104 cycles, which was 2.57 times that of the unreinforced defective specimen. The Fe-SMA plate did not change the fatigue crack propagation path but effectively slowed crack growth through local stiffness enhancement and activation-induced pre-compressive stress. Parametric analysis further showed that, among the investigated numerical cases, an activation temperature of 200 \u00b0C produced the largest predicted strengthening effect. Increasing the pore diameter from 0.5 mm to 2.0 mm reduced the reinforcement effect from 69.45% to 52.98%, and increasing the crack length from 10 mm to 50 mm reduced it from 65.41% to 35.53%. These results indicate that bonded Fe-SMA plates can effectively improve the fatigue performance of U-rib butt-welded joints with porosity defects, especially when applied before excessive crack growth occurs.<\/jats:p>","DOI":"10.3390\/ma19132902","type":"journal-article","created":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T14:56:42Z","timestamp":1783349802000},"page":"2902","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Experimental and Numerical Investigation on Fe-SMA Strengthening of U-Rib Butt-Welded Joints with Porosity Defects"],"prefix":"10.3390","volume":"19","author":[{"given":"Haoran","family":"Sui","sequence":"first","affiliation":[{"name":"School of Civil and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-5011-747X","authenticated-orcid":false,"given":"Yi","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Civil and Construction Engineering, Hunan Institute of Technology, Hengyang 421002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Yao","sequence":"additional","affiliation":[{"name":"Guangzhou Branch of China Road and Bridge Corporation, Guangzhou 510000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xu","family":"Zhou","sequence":"additional","affiliation":[{"name":"Guangzhou Branch of China Road and Bridge Corporation, Guangzhou 510000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xue","family":"Bai","sequence":"additional","affiliation":[{"name":"School of Civil and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7438-8843","authenticated-orcid":false,"given":"Jianxin","family":"Peng","sequence":"additional","affiliation":[{"name":"School of Civil and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"114400","DOI":"10.1016\/j.engstruct.2022.114400","article-title":"Effect of stress reversals on fatigue life evaluation of OSD considering the transverse distribution of vehicle loads","volume":"265","author":"Zou","year":"2022","journal-title":"Eng. Struct."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.ijfatigue.2017.05.021","article-title":"Experimental study on fatigue failure of rib-to-deck welded connections in orthotropic steel bridge decks","volume":"103","author":"Cheng","year":"2017","journal-title":"Int. J. Fatigue"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"04018114","DOI":"10.1061\/(ASCE)BE.1943-5592.0001344","article-title":"Fatigue life evaluation for deck-rib welding details of orthotropic steel deck integrating mean stress effects","volume":"24","author":"Cao","year":"2019","journal-title":"J. Bridge Eng."},{"key":"ref_4","first-page":"213","article-title":"Determination of manufacturing parameters of large section of continuous steel box beam with variable","volume":"44","author":"Dong","year":"2024","journal-title":"J. China Foreign Highw."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.tafmec.2019.02.015","article-title":"Fatigue process of rib-to-deck welded joints of orthotropic steel decks","volume":"101","author":"Wang","year":"2019","journal-title":"Theor. Appl. Fract. Mech."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"109294","DOI":"10.1016\/j.matdes.2020.109294","article-title":"Effects of residual stresses on fatigue crack propagation of an orthotropic steel bridge deck","volume":"198","author":"Berg","year":"2021","journal-title":"Mater. Des."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"109601","DOI":"10.1016\/j.matdes.2021.109601","article-title":"Experimental study on the root-deck fatigue crack on orthotropic steel decks","volume":"203","author":"Wang","year":"2021","journal-title":"Mater. Des."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1016\/j.ijfatigue.2005.07.017","article-title":"Fatigue cracks in longitudinal ribs of steel orthotropic deck","volume":"28","author":"Xiao","year":"2005","journal-title":"Int. J. Fatigue"},{"key":"ref_9","first-page":"1","article-title":"Experimental study of fatigue crack behavior of rib-to-rib butt welded connections in orthotropic steel decks","volume":"15","author":"Shakir","year":"2018","journal-title":"Lat. Am. J. Solids Struct."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"04020090","DOI":"10.1061\/(ASCE)BE.1943-5592.0001624","article-title":"Prediction of crack propagation in U-rib components based on the Markov Chain","volume":"25","author":"Guo","year":"2020","journal-title":"J. Bridge Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"11933","DOI":"10.1007\/s11665-024-09903-8","article-title":"Laser butt welding of 6.6-mm thick D406A ultrahigh strength steel: Part I-Porosity and lower surface depression","volume":"34","author":"Xie","year":"2025","journal-title":"J. Mater. Eng. Perform."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"108091","DOI":"10.1016\/j.engfailanal.2024.108091","article-title":"Fatigue behavior of RD joint in OSBD subjected to local corrosion at top plate","volume":"159","author":"Peng","year":"2024","journal-title":"Eng. Fail. Anal."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Fan, C.B., Da, L.T., Wang, K.C., Song, S.Y., and Chen, H.Y. (2023). Fatigue tests and failure mechanism of rib-to-deck welded joints in steel bridge. Sustainability, 15.","DOI":"10.3390\/su15032108"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"108993","DOI":"10.1016\/j.engfailanal.2024.108993","article-title":"Lifetime fatigue cracking behavior of weld defects in orthotropic steel bridge decks: Numerical and experimental study","volume":"167","author":"Luo","year":"2025","journal-title":"Eng. Fail. Anal."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"108532","DOI":"10.1016\/j.jcsr.2024.108532","article-title":"Coupled propagation behavior of multiple fatigue cracks in welded joints of steel-bridge","volume":"215","author":"Lu","year":"2024","journal-title":"J. Constr. Steel Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"109393","DOI":"10.1016\/j.ijfatigue.2025.109393","article-title":"Fatigue assessment of steel welds with an isolated surface porosity defect at the weld toe","volume":"205","author":"Ma","year":"2026","journal-title":"Int. J. Fatigue"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"128528","DOI":"10.1016\/j.ijheatmasstransfer.2026.128528","article-title":"Porosity formation and suppression mechanisms in oscillating laser-arc hybrid welding of aluminum alloys","volume":"261","author":"Xu","year":"2026","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"105359","DOI":"10.1016\/j.engfailanal.2021.105359","article-title":"Fatigue life evaluation of deck to U-rib welds in orthotropic steel deck integrating weldment size effects on welding residual stress","volume":"124","author":"Jiang","year":"2021","journal-title":"Eng. Fail. Anal."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"102827","DOI":"10.1016\/j.tafmec.2020.102827","article-title":"Evaluating stress intensity factors for surface cracks in an orthotropic steel deck accounting for the welding residual stresses","volume":"100","author":"Qiang","year":"2020","journal-title":"Theor. Appl. Fract. Mech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"112432","DOI":"10.1016\/j.tws.2024.112432","article-title":"Fatigue test and evaluation of U-rib butt welds in orthotropic steel decks","volume":"205","author":"Zhang","year":"2024","journal-title":"Thin-Walled Struct."},{"key":"ref_21","first-page":"92","article-title":"Fatigue cracking characteristics of butt welds in U-rib embedded section of steel bridge decks","volume":"52","author":"Jiang","year":"2024","journal-title":"J. South China Univ. Technol. (Nat. Sci. Ed.)"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"111017","DOI":"10.1016\/j.tws.2023.111017","article-title":"Fatigue performance improvement of U-rib butt-welded connections of steel bridge decks using externally bonded CFRP strips","volume":"191","author":"Jiang","year":"2023","journal-title":"Thin-Walled Struct."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"106237","DOI":"10.1016\/j.ijfatigue.2021.106237","article-title":"Novel fatigue strengthening solution for metallic structures using adhesively bonded Fe-SMA strips: A proof of concept study","volume":"148","author":"Wang","year":"2021","journal-title":"Int. J. Fatigue"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"117316","DOI":"10.1016\/j.engstruct.2023.117316","article-title":"Proactive strengthening of U-rib butt-welded joints in steel bridge decks using adhesively bonded Fe-SMA strips","volume":"301","author":"Lv","year":"2024","journal-title":"Eng. Struct."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"116800","DOI":"10.1016\/j.conbuildmat.2019.116800","article-title":"Iron-based shape memory alloy (Fe-SMA) for fatigue strengthening of cracked steel bridge connections","volume":"227","author":"Izadi","year":"2019","journal-title":"Constr. Build. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"110745","DOI":"10.1016\/j.engfailanal.2026.110745","article-title":"Experimental and numerical analysis of fatigue crack repair in Rib-to-Rib welded connections of orthotropic steel decks using CFRP and steel plates","volume":"190","author":"Shakir","year":"2020","journal-title":"Eng. Fail. Anal."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"138524","DOI":"10.1016\/j.conbuildmat.2024.138524","article-title":"The effect of random pitting on the degradation of mechanical behavior of Q345C steel","volume":"449","author":"Liu","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_28","first-page":"119","article-title":"Analysis of fatigue performance of double-sided welded details between steel bridge deck and longitudinal ribs under Chinese and European codes","volume":"215","author":"Liu","year":"2023","journal-title":"Highw. Automot. Appl."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/13\/2902\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T04:56:35Z","timestamp":1783486595000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/13\/2902"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,6]]},"references-count":28,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ma19132902"],"URL":"https:\/\/doi.org\/10.3390\/ma19132902","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,6]]}}}