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Quanfeng Song

Bio: Quanfeng Song is an academic researcher from Technical University of Denmark. The author has contributed to research in topics: Electric resistance welding & Spot welding. The author has an hindex of 3, co-authored 4 publications receiving 88 citations.

Papers
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Journal Article
TL;DR: In this paper, a parametric study was carried out on a Gleeble® machine, investigating the influence on the contact resistance of interface normal pressure, temperature, and base metal.
Abstract: Electrical contact resistance is of critical importance in resistance welding. In this article, the contact resistance is experimentally investigated for welding mild steel, stainless steel, and aluminum to themselves. A parametric study was carried out on a Gleeble® machine, investigating the influence on the contact resistance of interface normal pressure, temperature, and base metal.

71 citations

Journal ArticleDOI
01 May 2006
TL;DR: Finite element based numerical modeling programs for resistance welding are presently being improved as an important tool for development and optimization of complex joints as mentioned in this paper, and one of the most important tools for complex joints.
Abstract: Finite element based numerical modelling programs for resistance welding are presently being improved as an important tool for development and optimization of complex joints. One of the rem...

8 citations

Journal ArticleDOI
01 May 2006
TL;DR: In this paper, the authors presented an experimentally validated contact algorithm for resistance welding with a solid ring projection towards a flat ring, and the experimental results were in good agreement with the simulation prediction, showing the validity of the algorithm.
Abstract: Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiment, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in good agreement with the simulation prediction, showing the validity of the algorithm.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, an improved representation of both electrical contact resistance and thermal contact resistance (TCR) in Al to zinc-coated steel RSW process is presented, which can be used to guide future welding schedule development or electrode geometry design for the RSW of Al to steel.

68 citations

Journal ArticleDOI
TL;DR: In this paper, an integrated experimental/numerical methodology was proposed to test the SPS model against experiments and to self-consistently estimate the overall set of unknown SPS contact resistances.
Abstract: The intricate bulk and contact multiphysics of spark plasma sintering (SPS) together with the involved non-linear materials’ response make the process optimization very difficult both experimentally and computationally. The present work proposes an integrated experimental/numerical methodology, which simultaneously permits the developed SPS model to be reliably tested against experiments and to self-consistently estimate the overall set of unknown SPS contact resistances. Unique features of the proposed methodology are: (a) simulations and experiments are conducted in current control mode (SPS-CCm); (b) the SPS model couples electrothermal and displacement fields; (c) the contact multiphysics at the sliding punch/die interface is modeled during powder sintering using a moving mesh/moving boundary technique; (d) calibration and validation procedures employ both graphite compact and conductive WC powder samples. The unknown contact resistances are estimated iteratively by minimizing the deviation between predictions and on-line measurements (i.e., voltage, die surface temperature, and punch displacement) for three imposed currents (i.e., 1,900, 2,100, 2,700 A) and 20 MPa applied pressure. An excellent agreement is found between model predictions and measurements. The results show that the SPS bulk and contact multiphysics can be accurately reproduced during densification of ultrafine binderless WC powder. The results can be used to benchmark contact resistances in SPS systems applicable to graphite and conductive (WC) powder samples. The SPS bulk and contact multiphysics phenomena arising during sintering of ultrafine binderless WC powders are finally discussed. A direct correlation between sintering microstructure, sintering temperature, and heating rate is established. The developed self-consistent SPS model can be effective used as an aiding tool to design optimum SPS experiments, predict sintering microstructure, or benchmark SPS system hardware or performances.

58 citations

Journal ArticleDOI
TL;DR: In this article, the influence of current intensity to surface shaped features on welding seam was discussed and the comparison between AZ31B joints and Al 7075 joints was conducted, showing that the resistant heat source promoted significant grain refinement and hardness improvement in the weld nugget zone.

46 citations

Journal ArticleDOI
TL;DR: In this article, the effect of welding process parameters on the shear strength, tensile strength, nugget diameter and the observed failure mode was analyzed for galvannealed high strength interstitial free steel sheets of 1.6mm thickness.

39 citations

Journal ArticleDOI
TL;DR: In this article, the Gurson model is used to model the deformation of a spot weld near the heat affected zone (HAZ), and the authors find that the weld diameter is related to the tensile shear force (TSF) and the associated displacement.
Abstract: Ductile plug failure of resistance spot welded shear-lab specimens is studied by full 3D finite element analysis, using an elastic-viscoplastic constitutive relation that accounts for nucleation and growth of microvoids to coalescence (The Gurson model). Tensile properties and damage parameters are based on uni-axial tensile testing of the basis material, while the modelled tensile response of the shear-lab specimens is compared to experimental results for the case of a ductile failure near the heat affected zone (HAZ). A parametric study for a range of weld diameters is carried out, which makes it possible to numerically relate the weld diameter to the tensile shear force (TSF) and the associated displacement, u TSF , respectively. Main focus in the paper is on modelling the localization of plastic flow and the corresponding damage development in the vicinity of the spot weld, near the HAZ. For decreasing weld diameter, localization of plastic flow may be observed to occur in the weld nugget, introducing significant shearing. Due to these competing mechanisms a critical transition radius of the weld may be found. However, due to the limitation of the Gurson model in describing ductile failure at very low stress triaxiality, further analysis of the shear failure is omitted.

38 citations