{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T04:19:20Z","timestamp":1772252360014,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2018,3,5]],"date-time":"2018-03-05T00:00:00Z","timestamp":1520208000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>Shot peening is an attractive technique for fatigue enhanced performance of metallic components, because it increases fatigue crack initiation life prevention and retards early crack growth. Engineering design based on fatigue crack propagation predictions applying the principles of fracture mechanics is commonly used in aluminum structures for aerospace engineering. The main purpose of present work was to analyze the effect of shot peening on the fatigue crack propagation of the 7475 aluminum alloy, under both constant amplitude loading and periodical overload blocks. The tests were performed on 4 and 8 mm thickness specimens with stress ratios of 0.05 and 0.4. The analysis of the shot-peened surface showed a small increase of the micro-hardness values due to the plastic deformations imposed by shot peening. The surface peening beneficial effect on fatigue crack growth is very limited; its main effect is more noticeable near the threshold. The specimen\u2019s thickness only has marginal influence on the crack propagation, in opposite to the stress ratio. Periodic overload blocks of 300 cycles promotes a reduction of the fatigue crack growth rate for both intervals of 7500 and 15,000 cycles.<\/jats:p>","DOI":"10.3390\/app8030375","type":"journal-article","created":{"date-parts":[[2018,3,6]],"date-time":"2018-03-06T07:37:25Z","timestamp":1520321845000},"page":"375","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Effects of Shot-Peening and Stress Ratio on the Fatigue Crack Propagation of AL 7475-T7351 Specimens"],"prefix":"10.3390","volume":"8","author":[{"given":"Nat\u00e1lia","family":"Ferreira","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, Rua Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1152-020X","authenticated-orcid":false,"given":"Pedro","family":"Antunes","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, Rua Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0295-1841","authenticated-orcid":false,"given":"Jos\u00e9","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, Rua Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"given":"Jos\u00e9","family":"D. M. Costa","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, Rua Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3334-4945","authenticated-orcid":false,"given":"Carlos","family":"Capela","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, Rua Lu\u00eds Reis Santos, Coimbra 3030-788, Portugal"},{"name":"Department of Mechanical Engineering, Instituto Polit\u00e9cnico de Leiria, ESTG, Morro do Lena\u2014Alto Vieiro, Leiria 2400-901, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,3,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1053","DOI":"10.1016\/j.ijfatigue.2004.03.007","article-title":"High cycle fatigue behavior prediction of shot-peened parts","volume":"26","author":"Fathallah","year":"2004","journal-title":"Int. J. Fatigue"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/j.ijfatigue.2013.04.021","article-title":"Fatigue behavior of X70 microalloyed steel after severe shot peening","volume":"55","author":"Bagherifard","year":"2013","journal-title":"Int. J. Fatigue"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.engfracmech.2011.06.011","article-title":"Fatigue behavior of a low alloy steel with nanostructured surface obtained by severe shot peening","volume":"81","author":"Bagherifard","year":"2012","journal-title":"Eng. Fract. Mech."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/j.jmatprotec.2009.10.005","article-title":"Shot peening on the high-strength magnesium alloy AZ80\u2014effect of peening media","volume":"210","author":"Zhang","year":"2010","journal-title":"J. Mater. Process. Technol."},{"key":"ref_5","first-page":"15","article-title":"Some aspects of the influence of microstructure on fatigue resistance","volume":"Volume I","author":"Lutjering","year":"1996","journal-title":"Fatigue 96, Proceedings of the Sixth International Fatigue Congress, Berlin, Germany, 6\u201310 May 1996"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/S0142-1123(99)00123-1","article-title":"A new approach to the correlation between the coefficient and the exponent in the power law equation of fatigue crack growth","volume":"22","author":"Bergner","year":"2000","journal-title":"Int. J. Fatigue"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/S0142-1123(01)00006-8","article-title":"The material-dependent variability of fatigue crack growth rates of aluminium alloys in the Paris regime","volume":"23","author":"Bergner","year":"2001","journal-title":"Int. J. Fatigue"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/0142-1123(82)90065-2","article-title":"Measurement of fatigue crack closure through electron microscopy","volume":"4","author":"Sunder","year":"1982","journal-title":"Int. J. Fatigue"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/j.msea.2012.01.125","article-title":"Effect of repeated impacts on mechanical properties and fatigue fracture morphologies of 6061-T6 aluminium subject to laser peening","volume":"539","author":"Zhou","year":"2012","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/j.ijfatigue.2016.08.005","article-title":"Effect of laser peening and shot peening on fatigue striations during FCGR study of Ti6Al4V","volume":"93","author":"Pant","year":"2016","journal-title":"Int. J. Fatigue"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1111\/j.1460-2695.1984.tb00188.x","article-title":"On the overload induced fatigue crack propagation behavior in aluminium and steel alloys","volume":"7","author":"Vecchio","year":"1984","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1016\/0013-7944(89)90195-1","article-title":"Mechanisms associated with transient fatigue crack growth under variable amplitude loading: An experimental and numerical study","volume":"32","author":"Blom","year":"1989","journal-title":"Eng. Fract. Mech."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1016\/0013-7944(89)90153-7","article-title":"Effect of yield strength and single overload cycles on effective stress intensity range ratio in 6061-T6 Alalloy","volume":"34","author":"Krumar","year":"1989","journal-title":"Eng. Fract. Mech."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1111\/j.1460-2695.1992.tb01284.x","article-title":"The effect of intermediate heat treatments on overload induced retardations during fatigue crack growth in an Al-alloy","volume":"15","author":"Ling","year":"1992","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/0142-1123(93)90078-5","article-title":"Fracture modes encountered following the application of a major tensile overload cycle","volume":"15","author":"Damri","year":"1993","journal-title":"Int. J. Fatigue"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1111\/j.1460-2695.1996.tb00958.x","article-title":"Some aspects of fatigue crack growth retardation behaviour following tensile overloads in a structural steel","volume":"19","author":"Shuter","year":"1996","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1460-2695.1983.tb01135.x","article-title":"Influence of the overload on the fatigue crack growth in steels","volume":"6","author":"Robin","year":"1983","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1111\/j.1460-2695.1990.tb00601.x","article-title":"Effect of specimen geometry on fatigue crack growth in plane strain\u2014II. Overload response","volume":"13","author":"Shercliff","year":"1990","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/0142-1123(93)90175-P","article-title":"On the mechanisms and behaviour of overload retardation in AISI 304 stainless steel","volume":"15","author":"Shin","year":"1993","journal-title":"Int. J. Fatigue"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1016\/0013-7944(89)90101-X","article-title":"Modelling and measurement of crack closure and crack growth following overloads and underloads","volume":"33","author":"Dexter","year":"1989","journal-title":"Eng. Fract. Mech."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1111\/j.1460-2695.1996.tb01023.x","article-title":"Transient fatigue crack growth behaviour following single overloads at high stress ratios","volume":"19","author":"Tsukuda","year":"1996","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1379","DOI":"10.1016\/S0013-7944(02)00119-4","article-title":"Evaluation of overload effects on fatigue crack growth and closure","volume":"70","author":"Borrego","year":"2003","journal-title":"Eng. Fract. Mech."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"S47","DOI":"10.1016\/S0142-1123(99)00055-9","article-title":"An evaluation of DKeff estimation procedures on 6061-T6 and 2024-T3 aluminium alloys","volume":"21","author":"Donald","year":"1999","journal-title":"Int. J. Fatigue"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"S35","DOI":"10.1016\/S0142-1123(99)00054-7","article-title":"Service load fatigue damage\u2013\u2013A historical perspective","volume":"21","author":"Paris","year":"1999","journal-title":"Int. J. Fatigue"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1046\/j.1460-2695.2001.00383.x","article-title":"Fatigue crack growth and crack closure in an AlMgSi alloy","volume":"24","author":"Borrego","year":"2001","journal-title":"Fatigue Fract. Eng. Mater. Struct."},{"key":"ref_26","unstructured":"The American Standard SAE J443 (1968). Procedures for Using Standard Shot Peening Test Strip, American Standard."},{"key":"ref_27","unstructured":"The American Standard (2009). Aerospace Materials Division, American Standard. SAE, Shot Peening, SAE AMS 2430."},{"key":"ref_28","unstructured":"American Society for Testing and Materials (2000). Standard Test Method for Microhardness of Materials. Annual Book of ASTM Standards, ASTM."},{"key":"ref_29","unstructured":"International Organization for Standardization (1996). DIN EN ISO 4288: Geometrical Product Specifications (GPS). Surface Texture: Profile Method: Rules and Procedures for the Assessment of Surface Texture, ISO."},{"key":"ref_30","unstructured":"American Society for Testing and Materials (2015). Standard Test Method for Vickers Indentation Hardness of Advanced Ceramics, ASTM."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1321","DOI":"10.1016\/j.ijfatigue.2004.04.004","article-title":"Microstructure dependent fatigue crack growth in aged hardened aluminium alloys","volume":"26","author":"Borrego","year":"2004","journal-title":"Int. J. Fatigue"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.ijfatigue.2014.03.016","article-title":"A numerical study of plasticity induced crack closure under plane strain conditions","volume":"71","author":"Antunes","year":"2015","journal-title":"Int. J. Fatigue"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1016\/S0142-1123(00)00048-7","article-title":"Identification of Fatigue Crack Propagation Modes with Roughness Measurements","volume":"22","author":"Antunes","year":"2000","journal-title":"Int. J. Fatigue"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/S0013-7944(97)00085-4","article-title":"Fatigue shape analysis for corner cracks at fastener holes","volume":"59","author":"Lin","year":"1998","journal-title":"Eng. Fract. Mech."},{"key":"ref_35","unstructured":"Branco, R. (2006). Numerical Study of Fatigue Crack Growth in MT Specimens. [Master\u2019s Thesis, Department of Mechanical Engineering, University of Coimbra]."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.ijfatigue.2015.03.017","article-title":"Fatigue crack growth behaviour in the LCF regime in a shot peened steam turbine blade material","volume":"82","author":"He","year":"2016","journal-title":"Int. J. Fatigue"}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/8\/3\/375\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:57:35Z","timestamp":1760194655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/8\/3\/375"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,3,5]]},"references-count":36,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2018,3]]}},"alternative-id":["app8030375"],"URL":"https:\/\/doi.org\/10.3390\/app8030375","relation":{"has-preprint":[{"id-type":"doi","id":"10.20944\/preprints201801.0219.v1","asserted-by":"object"}]},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,3,5]]}}}