{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T10:31:53Z","timestamp":1789727513873,"version":"4.0.1"},"reference-count":28,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2020,9,14]],"date-time":"2020-09-14T00:00:00Z","timestamp":1600041600000},"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":["51675414"],"award-info":[{"award-number":["51675414"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2017YFD0700200"],"award-info":[{"award-number":["2017YFD0700200"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>A laser-assisted high-speed shearing (LAHSS) method has been proposed for metal bars, which prefabricates equally spaced fracture-start kerfs by Nd:Yag laser to make stress concentration, and applies a high-speed load to complete fracture separation. Comparative tests were conducted for Q235, 40Cr, and 304 steel bars, and the effects of fracture-start kerfs and axial clearance were investigated on the fracture section. Moreover, the fracture behavior was demonstrated by numerical simulation, and the micro-fracture mechanism was revealed by fractographic analysis. The numerical simulation results show that the material damage concentrates along with the kerf tips with peak equivalent plastic strain, and the corresponding stress triaxiality drops to almost zero at the kerf tip, which reveals that the material is subjected to pure shearing at kerf tip; the Max. loading force is reduced by 15.2%\u201329.6%, and the impact energy is decreased by 29.8%\u201346.9% for the three types of bar material. The experimental results showed that the fracture-start kerfs effectively inhibited the plastic deformation stage, and higher precision blanks were obtained in the LAHSS test: roundness error improved from 2.7%\u201310.9% to 1.1%\u20132.6%, Max. bending deflection decreased from 1.3\u20133.4 mm to 0.4\u20131.0 mm, and flatness error dropped from 0.9\u20133.3 mm to 0.3\u20130.7 mm. The fractographic analysis reveals that the crack initiation is related to alternative V-shape micro-notches at the laser-affected zone; the predominant fracture mechanism involves mode II microvoid coalescence at the main fracture plane; smaller and less elongated dimples were formed in 40Cr steels due to higher number density of grains and pinning effect of second-phase particles compared to Q235 and 304 steel bars.<\/jats:p>","DOI":"10.3390\/ma13184073","type":"journal-article","created":{"date-parts":[[2020,9,14]],"date-time":"2020-09-14T09:04:53Z","timestamp":1600074293000},"page":"4073","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Investigation of Fracture Behavior and Mechanism in High-Speed Precise Shearing for Metal Bars with Prefabricated Fracture-Start Kerfs"],"prefix":"10.3390","volume":"13","author":[{"given":"Yuanzhe","family":"Dong","sequence":"first","affiliation":[{"name":"School of Mechanical Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2598-650X","authenticated-orcid":false,"given":"Jinqiang","family":"Ning","sequence":"additional","affiliation":[{"name":"George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peng","family":"Dong","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yujian","family":"Ren","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9191-9017","authenticated-orcid":false,"given":"Shengdun","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1470","DOI":"10.1177\/0954406214543672","article-title":"Experimental investigation on new low cycle fatigue precision cropping process","volume":"229","author":"Zhao","year":"2015","journal-title":"Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"777","DOI":"10.1007\/s00170-017-0174-8","article-title":"Acoustic emission characteristics in eccentric rotary cropping process of stainless steel tube","volume":"92","author":"Li","year":"2017","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.ijmecsci.2018.04.039","article-title":"Research on critical loading force in precision cropping system based on hydraulic compensation","volume":"142\u2013143","author":"Zhang","year":"2018","journal-title":"Int. J. Mech. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1016\/j.ijmecsci.2013.09.019","article-title":"Investigation on the influences of clearance and notch-sensitivity on a new type of metal-bar non-chip fine-cropping system","volume":"76","author":"Zhong","year":"2013","journal-title":"Int. J. Mech. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1007\/s00170-018-1979-9","article-title":"Study on the pre-shearing cropping process of steel bars","volume":"97","author":"Hu","year":"2018","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_6","first-page":"151","article-title":"Mechanics of High-Speed Bar Cropping","volume":"180","author":"Organ","year":"1965","journal-title":"Proc. Inst. Mech. Eng. Conf. Proc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.jmatprotec.2007.04.065","article-title":"An investigation of material flow analysis in fineblanking process","volume":"192\u2013193","author":"Thipprakmas","year":"2007","journal-title":"J. Mater. Process. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1016\/0890-6955(92)90011-5","article-title":"Brittle precision cropping of metal materials","volume":"32","author":"Chen","year":"1992","journal-title":"Int. J. Mach. Tools Manuf."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.msea.2007.09.098","article-title":"Numerical simulation and experiments of precision bar cutting based on high speed and restrained state","volume":"499","author":"Song","year":"2009","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1179\/174328008X277795","article-title":"High strain rate properties of metals and alloys","volume":"53","author":"Armstrong","year":"2008","journal-title":"Int. Mater. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.1061\/(ASCE)EM.1943-7889.0000557","article-title":"Dynamic tensile and compressive behaviors of mild steel at wide range of strain rates","volume":"139","author":"Singh","year":"2013","journal-title":"J. Eng. Mech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/j.mechmat.2014.05.001","article-title":"Dynamic vs. quasi-static shear failure of high strength metallic alloys: Experimental issues","volume":"80","author":"Dragon","year":"2015","journal-title":"Mech. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.engfracmech.2015.05.020","article-title":"Dynamic crack initiation measurements in a four-point split Hopkinson bending device","volume":"133","author":"Henschel","year":"2015","journal-title":"Eng. Fract. Mech."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"105308","DOI":"10.1016\/j.ijmecsci.2019.105308","article-title":"Laser-assisted cyclic chipless splitting for hard-to-cut thick wall tubes and fatigue fracture mechanism analysis","volume":"168","author":"Dong","year":"2020","journal-title":"Int. J. Mech. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"985","DOI":"10.1016\/j.optlastec.2010.01.019","article-title":"A study of process parameters during pulsed Nd:YAG laser notching of C70S6 fracture splitting connecting rods","volume":"42","author":"Zheng","year":"2010","journal-title":"Opt. Laser Technol."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Dai, L., Niu, G., and Ma, M. (2020). Microstructure Evolution and Mechanical Properties of Tempered 5140 Alloy Steel after Proton Irradiation at Different Temperatures. Materials, 13.","DOI":"10.3390\/ma13132910"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Wu, J., Zhan, G., He, L., Zou, Z., Zhou, T., and Du, F. (2020). Tribological performance of micro-groove tools of improving tool wear resistance in turning AISI 304 process. Materials, 13.","DOI":"10.3390\/ma13051236"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Li, Y., Song, J., Fu, J., Ju, L., Du, S., and Ting, K.L. (2006, January 6\u20137). Design and research on the precise bar cutting machine based on high speed and restrained state. Proceedings of the IET Conference Publications, Hangzhou, China.","DOI":"10.1049\/cp:20060780"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"64","DOI":"10.3901\/CJME.2000.01.064","article-title":"Research on the energy economization of electro-hydraulic hammer","volume":"13","author":"Lei","year":"2000","journal-title":"Chin. J. Mech. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4879","DOI":"10.1016\/j.ijsolstr.2008.04.020","article-title":"Elastic stress distributions for hyperbolic and parabolic notches in round shafts under torsion and uniform antiplane shear loadings","volume":"45","author":"Zappalorto","year":"2008","journal-title":"Int. J. Solids Struct."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/j.msea.2015.05.073","article-title":"Determination of Johnson cook material and failure model constants and numerical modelling of Charpy impact test of armour steel","volume":"640","author":"Banerjee","year":"2015","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1284","DOI":"10.1016\/j.jmatprotec.2013.03.001","article-title":"Prediction of ductile fracture for advanced high strength steel with a new criterion: Experiments and simulation","volume":"213","author":"Lou","year":"2013","journal-title":"J. Mater. Process. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/0013-7944(85)90052-9","article-title":"Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures","volume":"21","author":"Johnson","year":"1985","journal-title":"Eng. Fract. Mech."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, B., Liu, Z., Hou, X., and Zhao, J. (2018). Influences of cutting speed and material mechanical properties on chip deformation and fracture during high-speed cutting of inconel 718. Materials, 11.","DOI":"10.3390\/ma11040461"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1016\/j.ijsolstr.2012.10.007","article-title":"Extension of a shear-controlled ductile fracture model considering the stress triaxiality and the Lode parameter","volume":"50","author":"Lou","year":"2013","journal-title":"Int. J. Solids Struct."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1071","DOI":"10.1016\/j.ijplas.2007.09.004","article-title":"A new model of metal plasticity and fracture with pressure and Lode dependence","volume":"24","author":"Bai","year":"2008","journal-title":"Int. J. Plast."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Dong, Y., Ren, Y., Fan, S., Wang, Y., and Zhao, S. (2020). Investigation of notch-induced precise splitting of different bar materials under high-speed load. Materials, 13.","DOI":"10.3390\/ma13112461"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.commatsci.2011.10.021","article-title":"Computational approach using Johnson-Cook model on dual phase steel","volume":"54","author":"Prawoto","year":"2012","journal-title":"Comput. Mater. Sci."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/13\/18\/4073\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:09:44Z","timestamp":1760177384000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/13\/18\/4073"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,9,14]]},"references-count":28,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2020,9]]}},"alternative-id":["ma13184073"],"URL":"https:\/\/doi.org\/10.3390\/ma13184073","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,9,14]]}}}