• Title/Summary/Keyword: Self-piercing rivet(SPR)

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Finite Element Analysis for Design of Divided Shank of Self-Piercing Rivet (분리형 섕크를 갖는 SPR의 형상 설계를 위한 유한요소해석)

  • Kim, Kwan-Woo;Kim, Dongbum;Cho, Hae-Yong
    • Journal of Welding and Joining
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    • v.34 no.2
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    • pp.54-58
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    • 2016
  • SPR(Self-Piercing rivet) is mechanical element of joining sheet metal components without the need for pre-punched or pre-drilled holes. Newly designed SPR is developed for high joining strength and shearing strength than semi-tubular rivet. In this study, divided shank of self-piercing rivet were designed for joining DP440 and SILAFONT. Newly designed SPR was simulated by using FEM code DEFORM-3D. In simulations of SPR process, various shape of self-piercing rivet were considered for semi-tubular and newly designed SPR. In other to examine the joinability, joining load and lap-shear load of newly designed SPR were compared with semi-tubular by simulated results and experimental ones.

Design of self-piercing rivet to joint in advanced high strength steel and aluminium alloy sheets (초고장력강과 알루미늄 합금의 접합을 위한 SPR 설계)

  • Kim, Dongbum;Qiu, Yuangen;Cho, Hae-Yong
    • Journal of Welding and Joining
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    • v.33 no.3
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    • pp.75-80
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    • 2015
  • Self-piercing riveting is an joining method of advanced high strength steels (AHSS) and other dissimilar materials. It has attracted considerable interest from the automotive industry. The SPR has become an interesting alternative joining technique for difficult to weld materials such as steels and aluminium alloys. In this paper, self-piercing rivet and anvil for SPR were designed for the joining conditions with AHSS and aluminium alloy. Various conditions of SPR were simulated for the design of rivets and anvils. The simulated results were in good agreement with experimental ones. As a result, over HV500 rivet is desirable to joint SPFC780 AHSS and aluminum alloy.

Assessment of Fatigue Life on Curved Self-Piercing Rivet Joint Specimen (곡률을 갖는 셀프-피어싱 리벳 접합시편의 피로수명 평가)

  • Kim, Min-Gun;Cho, Seok-Swoo;Kim, Dong-Youl
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.1
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    • pp.71-79
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    • 2010
  • One of methods that accomplish fuel-efficient vehicle is to reduce the overall vehicle weight by using aluminum structure typically for cross members, rails and panels in body and chassis. For aluminum structures, the use of Self Piercing Rivet(SPR) is a relatively new joining technique in automotive manufacture. To predict SPR fatigue life, fatigue behavior of SPR connections needs to be investigated experimentally and numerically. Tests and simulations on lap-shear specimen with various material combinations are performed to obtain the joining strength and the fatigue life of SPR connections. A Finite element model of the SPR specimen is developed by using a FEMFAT SPR pre-processor. The fatigue lives of SPR specimens with the curvature are predicted using a FEMFAT 4.4e based on the liner finite element analysis.

Influence of the Flow Stress of the Rivet on the Numerical Prediction of the Self-Piercing Rivet (SPR) Joining (Self-Piercing Rivet 접합공정의 수치예측에 미치는 리벳 유동응력의 영향)

  • Kim, S.H.;Bae, G.;Song, J.H.;Park, K.Y.;Park, N.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.257-264
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    • 2020
  • This paper is concerned with the influence of the plastic property of the rivet on the numerical prediction of the Self-Piercing Rivet (SPR) Joining. In order to predict the plastic property of the rivet, a ring compression specimen was directly fabricated from the rivet used for the mechanical joining of dissimilar materials, and the FE analysis together with the ring compression test was iteratively carried out by changing the plastic property of the rivet. For reliable FE analysis, a friction coefficient was estimated based on a friction calibration curve, measuring the reductions in inner diameter and height of the ring specimen after the compression test. From each simulation result, the force-displacement curves were then compared from each other so as to obtain the rivet plastic property that shows good agreement with the experimental result. The SPR joining between GA590 1.0t and Al5052 2.0t was conducted, and the numerical prediction was performed with the use of the plastic property evaluated based on the inverse analysis and the one referred from Mori et al. [11]. Comparison of the experiment and the numerical predictions in terms of the interlock and bottom thickness revealed that the reliable evaluation of the plastic property of the rivet is necessary for the trustworthy numerical prediction of the SPR joining.

Forging Process Design of Self-Piercing Rivet for Joining dissimilar Sheet Metals (이종재료 접합을 위한 Self-Piercing Rivet의 단조공정설계)

  • Kim, Dong-Bum;Lee, Mun-Yong;Park, Byung-Joon;Park, Jong-Kweon;Cho, Hae-Yong
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.6
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    • pp.802-807
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    • 2012
  • Self-piercing rivet is sheet joining method. It is being used more to join aluminum alloy sheets. Self-piercing riveting is a large-deformation process that involves piercing. The self-piercing rivet, under the press from the punch, pierces the top sheet and forms a mechanical interlock with the bottom sheet. In this study, forging process was designed for manufacturing self-piercing rivet. The forging process has been simulated by using commercial FEM code DEFORM-2D. In simulation of forging process for manufacturing rivet, process sequence, formability, forging load, and distributions of stress and strain were investigated. The suitable forging process could be designed by comparisons of simulation results. The developed process consists of four stages: upsetting, first chamfering, back extrusion, and second chamfering. The simulated results for forging process were confirmed by experimental trials with the same conditions.

CRUSHING CHARACTERISTIC OF DOUBLE HAT-SHAPED MEMBERS OF DIFFERENT MATERIALS JOINED BY ADHESIVE BONDING AND SELF-PIERCING RIVET

  • Lee, M.H.;Kim, H.Y.;Oh, S.I.
    • International Journal of Automotive Technology
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    • v.7 no.5
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    • pp.565-570
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    • 2006
  • The development of a light-weight vehicle is in great demand for enhancement of fule efficiency and dynamic performance. The vehicle weight can be reduced effectively by using lightweight materials such as aluminum and magnesium. However, if such materials are used in vehicles, there are often instances when different materials such as aluminum and steel need to be joined to each other. The conventional joining method, namely resistance spot welding, cannot be used in joining different materials. Self-piercing rivet(SPR) and adhesive bonding, however, are good alternatives to resistance spot welding. This paper is concerned with the crushing test of double hat-shaped member made by resistance spot welding, SPR and adhesive bonding. Various parameters of crashworthiness are analyzed and evaluated. Based on these results, the applicability of SPR and adhesive bonding are proposed as an alternative to resistance spot welding.

Analysis of the Numerical Simulation Accuracy in the CFRP-Al Alloy SPR Joint Process According to the CFRP Modeling Method (CFRP 모델링 기법에 따른 CFRP-Al합금 SPR 접합공정의 수치해석 정확도 분석)

  • Kim, S.H.;Park, N.;Song, J.H.;Noh, W.;Park, K.Y.;Bae, G.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.265-271
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    • 2020
  • The purpose of this paper is to analyze the numerical simulation accuracy according to the CFRP modeling method in the CFRP-Al alloy SPR (Self-Piercing Rivet) joint process. The mechanical properties of the CFRP, aluminum sheet are precisely obtained from the tensile test according to the loading direction. Additionally, the hardening curve of rivet was calculated from the inverse analysis of the machined rivet-ring compression test. For the CFRP-Al alloy SPR simulation, two kinds of the CFRP modeling methods were established based on the continuum and layer-by-layer approaches. The simulation results showed that the CFRP layer-by-layer modeling method can provide more reliable prediction shape of the fractured sheets and deformed rivet. This simulation technique can be used in evaluating the CFRP-Metal SPR performance and designing the SPR process conditions.

Assessment of Structural Stiffness and Fatigue Life in Self-Piercing Rivet(SPR) Joint of Car Body (차체 셀프-피어싱 리벳 접합의 구조강성 및 피로수명 평가)

  • Kim Min-gun;Lee Kun-chan;Lee Byung-jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.8 s.227
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    • pp.1174-1182
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    • 2004
  • Recently, Self Piercing Rivet(SPR) has been spotlighted in the automotive industry as a substitutive resort of spot welding and has also been watched by the designer as lightening a car body due to their superior assembly processes. Fatigue behavior of SPR joint needs to be investigated experimentally and numerically to predict its structural stiffness and fatigue life. Testing of lap-shear specimens with various material combinations is performed to obtain the joining strength and the fatigue life of SPR connections. The simulation of SPR lap-shear specimens is also conducted to obtain the structural stiffness of SPR connections under different material combinations. A Finite element model of the SPR lap-shear specimen is developed using a FEMFAT SPR pre-processor. The fatigue lift of SPR specimen is predicted using a FEMFAT 4.4e based on the liner finite element analysis.

Finite element analysis for joining glass fiber reinforced plastic and aluminium alloy sheets (유리섬유 강화 플라스틱과 알루미늄 합금 접합을 위한 유한요소해석)

  • Cho, Hae-Yong;Kim, Dongbum
    • Journal of Welding and Joining
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    • v.33 no.2
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    • pp.78-84
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    • 2015
  • Self-piercing rivet(SPR) is mechanical joining methods and which can be joining dissimilar materials. Unlike conventional riveting, SPR also needs no pre-drilled holes. During plastically deformation, SPR pierces upper sheet and joins it to under sheet. SPR has been mainly applied to the joining the automobile body and some materials, such as glass fiber reinforced polymer and aluminum alloy, which represent the sheet-formed materials for lightweight automobile. Glass fiber reinforced plastic(GFRP) has been considered as a partial application of the automobile body which is lighter than steels and stronger than aluminium alloys. It is needed SPR to join Al alloy sheets and GFRP ones. In this paper, in order to design the rivet and anvil, which are suitable for GFRP, the joinability was examined through simulations of SPR joining between GFRP and Al alloy sheets. For this study, AutoCAD was used for the modeling and the simulated using commercial FEM code DEFORM-2D. The simulated results for SPR process joining between GFRP and Al alloys were confirmed by the same conditions as experimental trials.