Assessing edge cracking resistance in AHSS automotive parts by the Essential Work of Fracture methodology Show others and affiliations
2017 (English) In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 896, article id 012102Article in journal (Refereed) Published
Abstract [en]
Lightweight designs and demanding safety requirements in automotive industry areincreasingly promoting the use of Advanced High Strength Steel (AHSS) sheets. Such steelspresent higher strength (above 800 MPa) but lower ductility than conventional steels. Their greatproperties allow the reduction of the thickness of automobile structural components withoutcompromising the safety, but also introduce new challenges to parts manufacturers. Thefabrication of most cold formed components starts from shear cut blanks and, due to the lowerductility of AHSS, edge cracking problems can appear during forming operations, forcing thestop of the production and slowing down the industrial process.Forming Limit Diagrams (FLD) and FEM simulations are very useful tools to predict fractureproblems in zones with high localized strain, but they are not able to predict edge cracking. Ithas been observed that the fracture toughness, measured through the Essential Work of Fracture(EWF) methodology, is a good indicator of the stretch flangeability in AHSS and can help toforesee this type of fractures.In this work, a serial production automotive component has been studied. The componentshowed cracks in some flanged edges when using a dual phase steel. It is shown that theconventional approach to explain formability, based on tensile tests and FLD, fails in theprediction of edge cracking. A new approach, based on fracture mechanics, help to solve theproblem by selecting steel grades with higher fracture toughness, measured by means of EWF.Results confirmed that fracture toughness, in terms of EWF, can be readily used as a materialparameter to rationalize cracking related problems and select AHSS with improved edgecracking resistance.
Place, publisher, year, edition, pages Institute of Physics (IOP), 2017. Vol. 896, article id 012102
National Category
Applied Mechanics
Research subject Solid Mechanics
Identifiers URN: urn:nbn:se:ltu:diva-66857 DOI: 10.1088/1742-6596/896/1/012102 ISI: 000424196000102 Scopus ID: 2-s2.0-85032458678 OAI: oai:DiVA.org:ltu-66857 DiVA, id: diva2:1161670
Conference 36th IDDRG Conference - Materials Modelling and Testing for Sheet Metal Forming, Munich, Germany, 2–6 July 2017
Note 2017-11-30 (rokbeg);Konferensartikel i tidskrift
2017-11-302017-11-302021-10-15 Bibliographically approved