Change search
Refine search result
1 - 10 of 10
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Barlo, A
    et al.
    Blekinge Institute of Technology, Sweden.
    Sigvant, M
    Blekinge Institute of Technology, Sweden; Volvo Cars, Sweden.
    Islam, M S
    Blekinge Institute of Technology, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Olofsson, E
    Volvo Cars, Sweden.
    Al-Fadhli, M
    Volvo Cars, Sweden.
    Pham, Q T
    Blekinge Institute of Technology, Sweden.
    Pilthammar, J
    Blekinge Institute of Technology, Sweden; Volvo Cars, Sweden.
    Odenberger, Eva-Lis
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Proposal of a New Tool for Pre-Straining Operations of Sheet Metals and an Initial Investigation of CR4 Mild Steel Formability2023In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-899X, Vol. 1284, article id 012079Article in journal (Refereed)
    Abstract [en]

    With the increased focus on reducing carbon emissions in the automotive industry, more advanced materials are introduced to reduce the vehicle weight, and more complex component geometries are designed to both satisfy customer demands and to optimize the vehicle aerodynamically. With the increase in component complexity, the strain paths produced during the forming operation of car body components often display a highly non-linear behavior which makes the task of failure prediction during the manufacturing feasibility studies more difficult. Therefore, CAE engineers need better capabilities to predict failure induced by strain path nonlinearity. This study proposes a new tool designed for creating bi-linear strain paths, by performing a pre-strain of a sheet large enough to cut out Nakajima specimens to perform the post-straining in any direction. From five pre-straining tests the tool present a stable pre-straining operation with a uniform strain field in a radius of 100 [mm] from the centre, corresponding to the region of interest of a Nakajima specimen. From the five pre-strained samples, different Nakajima specimens are cut transverse and longitudinal to the rolling direction and a failure prediction approach in an alternative, path independent evaluation space was used to predict the onset of necking with promising results.

  • 2.
    Barlo, A
    et al.
    Blekinge Institute of Technology, Sweden.
    Sigvant, M
    Blekinge Institute of Technology, Sweden; Volvo Cars, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Islam, M S
    Blekinge Institute of Technology, Sweden.
    Pilthammar, J
    Blekinge Institute of Technology, Sweden; Volvo Cars, Sweden.
    A Study of the Boundary Conditions in the ISO-16630 Hole Expansion Test2022In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Vol. 1238, article id 012031Article in journal (Refereed)
    Abstract [en]

    As new and more advanced sheet metal materials are introduced to the market, more accurate techniques for determination of failure limits are needed. One area that needs attention is edge formability, where the ISO-16630 standardized Hole Expansion Test currently is used to express this through the Hole Expansion Ratio. Over the years, this standard has been criticized for producing a large scatter in repeated tests. This paper investigates a new setup for the Hole Expansion Test which introduces draw beads into the setup to ensure sufficient restraining of the specimen during the test in an effort to reduced the scatter. In total 62 tests of a DP800 steel alloy were executed, but a large scatter in the results were still seen. It was therefore concluded that a lack of restraining force in the Hole Expansion Test was not the primary cause of the reported scatter seen in other tests.

  • 3.
    Odenberger, Eva-Lis
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Perez Caro, Lluis
    RISE, Swerea, IVF. Luleå University of Technology, Sweden.
    Marth, Stefan
    Luleå University of Technology, Sweden.
    Schill, Mikael
    DYNAmore GmbH, Germany.
    Oldenburg, Mats
    Luleå University of Technology, Sweden.
    Prediction of damage and fracture during forming simulations in Alloy 7182016In: Aerospace Technology Congress 2016: Swedish aerospace technology in a globalised world, 2016Conference paper (Other academic)
  • 4.
    Odenberger, Eva-Lis
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Perez Caro, Lluis
    RISE, Swerea, IVF. Luleå University of Technology, Sweden.
    Svensson, Lars-Erik
    University West, Sweden.
    Oldenburg, Mats
    Luleå University of Technology, Sweden.
    Steffenburg-Nordenström, Joachim
    GKN Aerospace, Sweden.
    Comparison of forming, welding and heat treatment simulations in LS-DYNA and MSC Marc2016In: Proceedings of the 10th International Conference on Trends in Welding Research & 9th International Welding Symposium of Japan Welding Society, 2016, p. 660-663Conference paper (Other academic)
    Abstract [en]

    The manufacturing of components for aero engine structures from a flat sheet to the final shape usually requires several steps that may introduce residual stresses and shape distortions in the part. Depending on the magnitude, sign and distribution with respect to the stresses induced by the service load, the remaining stresses may affect the service life of a component, especially when submitted to cyclic loading. Nowadays, several types of software that have the ability to predict the residual stresses and the final shape of a component subjected to various process steps are available. However, literature shows a lack of comparison studies among different software tools for multi-step simulations of a manufacturing process. In this study, the manufacturing process chain of an aerospace component including forming, welding and heat treatment in the nickel-based superalloy 718 is modelled and simulated using the two finite element software codes LS-DYNA and MSC.Marc. The results from the displacement of the blank in the punch stroke direction, the equivalent plastic strain and the von Mises stress are compared between both FE codes. The displacement of the blank after forming is slightly higher in LS-DYNA compared to MSC.Marc, as well as the equivalent plastic strain and the von Mises stress values. This tendency is also observed after trimming and welding. It can also be noted that the distribution of both strains and stresses on the trimmed and welded parts varies between the two compared codes, presumably due to the choice of different solver options, explicit and implicit.

  • 5.
    Odenberger, Eva-Lis
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF. Luleå University of Technology, Sweden.
    Perez Caro, Lluis
    RISE - Research Institutes of Sweden, Materials and Production, IVF. Luleå University of Technology, Sweden.
    Ņhlin, Hans
    Luleå University of Technology, Sweden.
    Oldenburg, Mats
    Luleå University of Technology, Sweden.
    Thermo-mechanical Material Characterization and Stretch-bend Forming of AA60162018In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Vol. 418, no 1Article in journal (Refereed)
    Abstract [en]

    Lightweight design has become increasingly in focus for the manufacturing industry. Global environmental challenges, goals and legislations imply that lighter and sustainable products are imperative to remain competitive. One example is stamped products made of aluminum alloys which are of interest to the automotive industry, where lightweight designs are essential. In order to increase formability and to produce more complex geometries in stamped aluminum components there is a need to develop hot forming techniques. The Finite Element Method (FEM) has enabled important advances in the study and design of competitive manufacturing procedures for metal parts. Predicting the final geometry of a component is a complex task, especially if the forming procedure occurs at elevated temperatures. This work presents selected results from thermo-mechanical material testing procedures, FE-analyses and forming validation tests in AA6016 material. The material tests are used to determine the thermo-mechanical anisotropic properties, strain rate sensitivity and formability (Forming Limit Curves, FLC) at temperatures up to 490°C. Stretch-bending tests are performed to compare predicted results with experimental observations such as punch force, strain levels, thinning, forming temperatures, springback and failure. It was found that the heat-treatment and forming at elevated temperatures substantially increased formability and that measured responses could in general be predicted if care was taken to model the initial blank temperatures, heat transfer and thermo-mechanical material properties. The room temperature case confirms the importance of considering anisotropy. © Published under licence by IOP Publishing Ltd.

  • 6.
    Perez Caro, Lluis
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF. Luleå University of Technology, Sweden.
    Schill, Mikael
    DYNAmore Nordic AB, Sweden.
    Haller, Kristian
    Acoustic Agree AB, Sweden.
    Odenberger, Eva Lis
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF. Luleå University of Technology, Sweden.
    Oldenburg, Mats
    Luleå University of Technology, Sweden.
    Damage and fracture during sheet-metal forming of alloy 7182019In: International Journal of Material Forming, ISSN 1960-6206, E-ISSN 1960-6214, Vol. 13, no 1, p. 15-28Article in journal (Refereed)
    Abstract [en]

    Forming nickel-based superalloy aero-engine components is a challenging process, largely because of the risk of high degree of springback and issues with formability. In the forming tests conducted on alloy 718 at room temperature, open fractures are observed in the drawbead regions, which are not predicted while evaluating the formability using the traditional forming-limit diagram (FLD). This highlights the importance of an accurate prediction of failure during forming as, in some cases, may severely influence the springback and thereby the accuracy of the predicted shape distortions, leading the final shape of the formed component out of tolerance. In this study, the generalised incremental stress-state dependent damage model (GISSMO) is coupled with the isotropic von Mises and the anisotropic Barlat Yld2000-2D yield criteria to predict the material failure in the forming simulations conducted on alloy 718 using LS-DYNA. Their effect on the predicted effective plastic strains and shape deviations is discussed. The failure and instability strains needed to calibrate the GISSMO are directly obtained from digital image correlation (DIC) measurements in four different specimen geometries i.e. tensile, plane strain, shear, and biaxial. The damage distribution over the drawbeads is measured using a non-linear acoustic technique for validation purposes. The numerical simulations accurately predict failure at the same regions as those observed in the experimental forming tests. The expected distribution of the damage over the drawbeads is in accordance with the experimental measurements. The results highlight the potential of considering DIC to calibrate the GISSMO in combination with an anisotropic material model for forming simulations in alloy 718.

    Download full text (pdf)
    fulltext
  • 7.
    Pham, Quoc Tuan
    et al.
    Blekinge Institute of Technology, Sweden.
    Islam, Md Shafiqul
    Blekinge Institute of Technology, Sweden.
    Barlo, Alexander
    Blekinge Institute of Technology, Sweden.
    Sigvant, Mats
    Volvo Cars, Sweden; Blekinge Institute of Technology, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Trana, Kristoffer
    Volvo Cars, Sweden.
    Modeling the strain localization of shell elements subjected to combined stretch–bend loads: Application on automotive sheet metal stamping simulations2023In: Thin-walled structures, ISSN 0263-8231, E-ISSN 1879-3223, Vol. 188, article id 110804Article in journal (Refereed)
    Abstract [en]

    This study presents a modeling approach for predicting strain localization during sheet metal stamping processes focused on automotive engineering applications. The so-called stretching-to-bending ratio, ρ, is proposed to characterize the loading conditions acting on an element during stamping processes. Then, localized strain or necking strain is suggested to be a function of ρ. Different stretch–bending tests with different tool radii, i.e., R3, R6, R10, and R50 are conducted for two automotive sheet metals, DP800 and AA6010, to identify their forming limits under combined stretch–bend loads. The calibrated necking limit curve of the AA6016 sheet is then employed in AutoForm R10 software to predict the necking and failure of a stamped panel. Agreement with the experimental observation of failure positions of the panel validates the usefulness of the proposed modeling approach in practice. 

  • 8.
    Pham, Quoc Tuan
    et al.
    Blekinge Institute of Technology, Sweden.
    Islam, Md Shafiqul
    Blekinge Institute of Technology, Sweden.
    Sigvant, Mats
    Blekinge Institute of Technology, Sweden;; Volvo Cars, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Prediction of forming limit diagram of automotive sheet metals using a new necking criterion2023In: Materials Research Proceedings, Association of American Publishers , 2023, p. 705-710Conference paper (Refereed)
    Abstract [en]

    A theoretical model for predicting the forming limit diagram of sheet metal, named MMFC2, was recently proposed by the authors based on the modified maximum force criterion (MMFC). This study examines the application of MMFC2 for two automotive sheets, DP800 and AA6016, which are widely used in making car body parts. Uniaxial tensile and bulge tests are conducted to calibrate constitutive equations for modeling the tested materials. The developed material models are employed into different frameworks such as MMFC, MMFC2, and Marciniak-Kuczynski (MK) models to forecast the forming limit curve (FLC) of the tested materials. Their predictions are validated by comparing with an experimental one obtained from a series of Nakajima tests. It is found that the derived results of MMFC2 are comparable to that of MK model and agreed reasonably with experimental data. Less computational time is the major advantage of MMFC2 against the MK model. 

  • 9.
    Pham, Quoc Tuan
    et al.
    Blekinge Institute of Technology, Sweden.
    Islam, Md Shafiqul
    Blekinge Institute of Technology, Sweden.
    Sigvant, Mats
    Blekinge Institute of Technology, Sweden; Volvo Cars, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Lee, Myoung-Gyu
    Seoul National University, South Korea.
    Kim, Young-Suk
    Kyungpook National University, South Korea.
    Improvement of modified maximum force criterion for forming limit diagram prediction of sheet metal2023In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 273, article id 112264Article in journal (Refereed)
    Abstract [en]

    This study presents a new criterion (MMFC2) for predicting the forming limit curve (FLC) of sheet metal. The strain path evolution of a critical element examined in a uniaxial tensile test is elaborated by incorporating the results of experimental measurement, finite element simulation, and theoretical prediction via the Modified Maximum Force Criterion (MMFC). A scaling factor is introduced to mimic the theoretical evaluation with the simulated one. It is believed that the rotation of the principal axes of the theoretically considering material point, which is initially co-axial with the external load coordinate, implicates the macro track of the strain path change. Furthermore, an optimal event of the second derivative of the axial rotations is proposed to indicate the strain localization and formulate the FLC. The performance of the proposed criterion is compared with that of the original MMFC in predicting the FLC of three automotive sheet metals, of which all related data were published in the Benchmark of Numisheet 2014 conference. The use of three different hardening laws and three yield functions is examined in the analogy. The comparison reveals that the results of MMFC2 are more sensitive to the employed constitutive model than that of MMFC. Furthermore, the proposed MMFC2 presents concordant results with the experimental data. Nakajima tests are conducted for CR4 mild steel sheets to validate the capacity of the proposed criterion. Well agreement between the experimentally measured data and theoretical prediction based on the Yld2k yield function verifies its usefulness in practice. © 2023 The Author(s)

  • 10.
    Rolseth, Anton
    et al.
    Jönköping University, Sweden.
    Carlsson, Marco
    MIT Massachusetts Institute of Technology, USA; Polestar Performance AB, Sweden.
    Ghassemali, Ehsan
    Jönköping University, Sweden.
    Pérez Caro, Lluís
    RISE Research Institutes of Sweden, Materials and Production, Manufacturing Processes.
    Jarfors, Anders E.W.
    Jönköping University, Sweden.
    Impact of functional integration and electrification on aluminium scrap in the automotive sector: A review2024In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 205, article id 107532Article in journal (Refereed)
    Abstract [en]

    The shift towards vehicle electrification must progress while simultaneously addressing sustainability challenges related to lightweighting, which is the intensifying need for high-quality primary aluminium, which demand cannot be met with recycled material with traditional compositional limits. To understand and predict the characteristics of future scrap mixtures, it is crucial to comprehend the evolving composition of new components and associated trends. This insight helps alloy design that accommodates higher impurities and, thus, a more thoughtful strategy for materials process development research. This review delves into the impact of electric motors, batteries, and functional integration. Notably, the analysis herein indicates a rise in magnesium (Mg) and a decrease in copper (Cu) and silicon (Si) contents in the future scrap mixtures due to more Al–Mg alloys such as those found in the 5xxx (Al–Mg) and 6xxx (Al–Mg–Si) series and an outflux of high Al–Si–Cu engine alloys. Gigacastings might counteract this trend based on their Si content and adoption and promote circularity principles by reducing alloy varieties. Reduced Si content in future scrap mixtures is also expected to boost sustainability since significant CO2 emissions from recycled alloys come from melting, controlled by the latent heat of fusion of the scrap mix. © 2024 The Authors

    Download full text (pdf)
    fulltext
1 - 10 of 10
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf