Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Post necking characterisation for sheet metal materials using full field measurement
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.ORCID-id: 0000-0001-9626-5406
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.ORCID-id: 0000-0002-7514-0513
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.ORCID-id: 0000-0001-7074-8960
Antal upphovsmän: 42016 (Engelska)Ingår i: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 238, s. 315-324Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

precise prediction of the post-necking behaviour of materials is needed to increase the precision of computer simulations with large deformations. Applications in which this need is encountered include crash, forming, and failure simulations. By using an optical full-field measurement of the localised deformation field, an effective and computationally fast method is presented to determine the relationship between true stress and true plastic strain, including post-necking behaviour. The presented stepwise modelling method is used to characterise heat-treated boron steel using thin sheet metal specimens. These results are validated with the results determined by a method based on inverse modelling. It can be concluded that the stepwise modelling method is considerably faster than the compared inverse modelling method. The method is also suitable for effectively determining element size dependency due to regularisation of the hardening behaviour needed for finite element analysis with strain localisation, e.g., for crash simulations

Ort, förlag, år, upplaga, sidor
2016. Vol. 238, s. 315-324
Nationell ämneskategori
Teknisk mekanik
Forskningsämne
Hållfasthetslära
Identifikatorer
URN: urn:nbn:se:ltu:diva-7653DOI: 10.1016/j.jmatprotec.2016.07.036ISI: 000383291500035Scopus ID: 2-s2.0-84979761844Lokalt ID: 60ea60e7-bbdb-410a-ad81-db321eb80b2cOAI: oai:DiVA.org:ltu-7653DiVA, id: diva2:980543
Anmärkning

Validerad; 2016; Nivå 2; 20160816 (andbra)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Ingår i avhandling
1. Material Characterization for Modelling of Sheet Metal Deformation and Failure
Öppna denna publikation i ny flik eller fönster >>Material Characterization for Modelling of Sheet Metal Deformation and Failure
2017 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Weight reduction is one possibility to reduce fuel consumption and emission of transportation vehicles. Sheet metals are often used in automotive and aerospace applications and therefore the weight reduction achieved by reducing the sheet metals thickness is an important contribution to weight reduction. Increasing the strength of sheet metal materials gives the opportunity to reduce the total weight while maintaining safety. To prove a maintained safety for parts with a decreased weight Finite Element (FE) simulations are commonly used. This leads to a high demand on the simulation precision of sheet metals, where an accurate prediction of the post-necking behaviour of materials is needed. Improved FE simulations are reducing time and costs during the development processes. 

One application to improve the strength of sheet metals in the automotive industry is the usage of ultra high strength steels, which has constantly increased in usage during the last decades. The development of the press hardening process, where sheet metal blanks are formed and quenched simultaneously, brings new design opportunities. Using press hardening tools with zones that uses different cooling rates sheet metal parts can be produced with tailored properties, to improve their performance. Simulating materials based on the microstructure demands high precision on the plasticity modelling for high strain values. 

In this thesis work a method to characterize the elasto plastic post necking behaviour of sheet metal materials, the Stepwise Modelling Method (SMM), is presented. The method uses full field measurements of the deformation field on the surface of tensile specimen. The hardening relation is modelled as a piecewise linear in a step by step procedure. The linear hardening parameter is adapted to reduce the residual between experimental and calculated tensile forces. The SMM is used to characterize the post necking behaviour of a ferritic boron steel and the results are compared with the commonly used inverse modelling method. It is shown that the stepwise modelling method characterizes the true stress, true plastic strain relation in an effective and computational efficient way. Furthermore, the SMM is used to characterize the stress state evolution during tensile testing, which is an important factor for failure and fracture modelling. This method is shown in an aerospace application for the nickel based super alloy Alloy 718. 

The results shows that the stepwise modelling method is an effective and efficient alternative method to characterize the deformation and failure of sheet metals. Based on the results of this method plasticity and fracture models can be characterized in future work.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå tekniska universitet, 2017
Serie
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Nationell ämneskategori
Materialteknik Maskinteknik Teknisk mekanik
Forskningsämne
Hållfasthetslära
Identifikatorer
urn:nbn:se:ltu:diva-62477 (URN)978-91-7583-845-8 (ISBN)978-91-7583-846-5 (ISBN)
Presentation
2017-05-12, E231, Luleå University of Technology, Luleå, 10:00 (Engelska)
Tillgänglig från: 2017-03-15 Skapad: 2017-03-13 Senast uppdaterad: 2017-11-24Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Marth, StefanHäggblad, Hans-åkeOldenburg, MatsÖstlund, Rickard

Sök vidare i DiVA

Av författaren/redaktören
Marth, StefanHäggblad, Hans-åkeOldenburg, MatsÖstlund, Rickard
Av organisationen
Material- och solidmekanik
I samma tidskrift
Journal of Materials Processing Technology
Teknisk mekanik

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 471 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf