Browsing by Author "Durandet, Y"

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    Effect of sheet material properties on residual stress profile in self-pierce riveted joint
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2012-11-07) Haque, R; Durandet, Y; Paradowska, AM
    Self-Piercing Riveting (SPR) is a high-speed mechanical fastening technique which does not require pre-drilling. During SPR, a tubular rivet is driven through the top sheet, piercing the bottom sheet without breaking through it, accompanied by flaring of the legs in the bottom sheet under the guidance of a suitable die. The rivet material should have adequate hardness to pierce the sheets, and sufficient ductility to deform in the bottom sheet without cracking, thus producing a mechanical interlock between the sheets. An increase in strength or thickness of the ply materials narrows down the operating window in terms of joint quality and performance. It is important to know the residual stress distribution arising from the riveting process, and its dependence on the ply materials properties. to ensure a sound joint. In this study, four different joints consisting of two different hardnesses of materials and two different hardnesses of rivets were examined. Residual stresses were measured on the strain scanner Kowari at ANSTO at selected critical locations. The study revealed that the hardness of the rivet and a ply material influence the magnitude and distribution of compressive residual stress in the rivet joint. It was observed that the maximum compressive residual stress occurred in the rivet leg in the transverse direction relative to plane of sheet. The challenges related to the application of neutron diffraction technique to the measurements of residual stress in the riveted joints are presented and discussed.
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    Evaluation of residual stress in SPR joint by neutron diffraction
    (Trans Tech Publication Inc., 2012-01-01) Haque, R; Beynon, JH; Kirstein, O; Wong, YC; Durandet, Y
    The feasibility of measuring residual stresses in Self-Pierce Riveted (SPR) joints by neutron diffraction was evaluated in this study. Despite the small dimensions involved, meaningful results were obtained. It was observed that residual stress in the rivet head was higher in the centre and lower at the edge. For the SPR joints examined, the maximum value of residual stress evaluated was 550MPa, compressive and occurred in the rivet leg. Stresses in material adjacent to the rivet wall and at a distance of three times the rivet radius from the rivet axis were not significant. The results are discussed with respect to the physical events involved during SPR. © 2011, Trans Tech Publications
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    Feasibility of measuring residual stress profile in different self-pierce riveted joints
    (Maney Publishing, 2012-01-01) Haque, R; Beynon, JH; Durandet, Y; Kirstein, O; Blacket, S
    The feasibility of measuring residual stresses in self-pierce riveted (SPR) joints by neutron diffraction technique was investigated. The main challenge involved dealing with the very small dimensions of SPR joints. Two different joints were examined: aluminium‐steel and steel‐steel. Even though small dimensions were involved, meaningful results were obtained. In the rivet head, tensile stress was observed for the steel‐steel sample, whereas only compressive stress was observed for the aluminium‐steel. The residual stress in the rivet head was higher at the centre and lower at the edge for both joints. Stresses in the sheet material beside the rivet wall and at a distance of three times the rivet radius from the rivet axis were not significant. For the SPR joints examined, the maximum value of residual stress was compressive and occurred in the rivet leg. The results are discussed according to the physical events involved during the process.© 2012, Maney Publishing
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    Optimising parameters for meaningful measurement of residual strain by neutron diffraction in self-pierce riveted joints
    (Maney Publishing, 2013-11-18) Haque, R; Durandet, Y; Wong, YC; Paradowska, AM; Beynon, JH; Blacket, S
    The aim of this work is to examine the uncertainties involved in measuring residual strain and their dependence on both the gauge volume of the neutron beam and the acquisition time in self pierce riveted (SPR) joints while using the neutron diffraction technique. The main challenge involved dealing with the very small dimensions of SPR joints and developing optimum instrument configuration that allowed faster and/or more accurate stress measurement in SPR while maintaining the same time resolution required for the millimetre scale of the problem. Two different gauge volumes were used (0.125 and 1.0 mm(3)), and two different measuring directions were chosen in order to examine the rotational accuracy of the sample table. All measurements were conducted in steel–steel joints. Even though small sizes were involved, meaningful results were obtained and measurement errors were reduced by optimising the instrument parameters. © 2013, Maney Publishing
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    Residual stress profiles in riveted joints of steel sheets
    (Taylor and Francis, 2014-12-28) Haque, R; Wong, YC; Paradowska, AM; Durandet, Y
    The residual stress profiles in two different self-piercing riveted (SPR) joints were characterised using the neutron diffraction technique. The joints were produced using semi-tubular steel rivets and carbon steel sheets of different thicknesses and hardnesses. The residual stress in the sheet material inside the bore of the rivet was compressive at the centre and the stress became tensile away from the centre. The stresses found in the semi-tubular rivet were compressive, with a lower magnitude in the rivet head compared with those in the rivet leg. For the SPR joints examined, the compressive residual stress in the rivet leg was greater for the thin joint than the thick joint, and this was due to the higher force gradient encountered during the rivet flaring stage. The originality of this work was to relate the residual stress profile to the physical event that occurred during the SPR process. © 2021 Informa UK Limited
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    Residual stresses in Al7075 alloy laser cladded with Al-12Si alloy powder
    (The Bragg Institute, Australian Nuclear Science and Technology Organisation, 2006-11-27) Durandet, Y; Bendeich, PJ; Ripley, MI; Liu, Q; Brandt, M
    Compared to conventional arc-welding processes commonly used to repair aluminium (Al) components, laser-cladding involves narrower heat affected zones (HAZ), lower overall heat input and less part distortion. With the development of high power lasers, it has become an attractive technology for the refurbishment of high value added structural airframe components in commercial and military aircrafts, especially those made of hard-to-weld age hardenable Al 7xxx series alloys. Laser cladding of 6.35mm thick rolled plates of Al7075 alloy was performed at IRIS using a high power Nd:YAG Laser and an Al-128i alloy powder as the filler repair material. Residual stress profiles through the clad plate thickness were measured using neutron diffraction scattering at ANSTO. Results showed the laser cladding pattern on residual stress profiles in directions longitudinal and transverse to the plate rolling direction. © The Authors
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    SPR characteristics curve and distribution of residual stress in self-piercing riveted joints of steel sheets
    (Hindawi, 2017-02-15) Haque, R; Wong, YC; Paradowska, AM; Blacket, S; Durandet, Y
    Neutron diffraction was used to describe the residual stress distributions in self-piercing riveted (SPR) joints. The sheet material displayed a compressive residual stress near the joint, and the stress gradually became tensile in the sheet material far away from the joint. The stress in the rivet leg was lower in the thick joint of the softer steel sheet than in the thin joint of the harder steel sheet. This lower magnitude was attributed to the lower force gradient during the rivet flaring stage of the SPR process curve. This study shows how the residual stress results may be related to the physical occurrences that happened during joining, using the characteristics curve. The study also shows that neutron diffraction technique enabled a crack in the rivet tip to be detected which was not apparent from a cross-section. © 2017 Rezwanul Haque et al. This is an open access article distributed under the Creative Commons Attribution License