• Title/Summary/Keyword: Spot Welded Section Members

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Collapse Analysis of Spot Welded Thin Section Members in a Vehicle Body Structure at Various Impact Velocities

  • Cha, Cheon-Seok;Chung, Jae-Oh;Park, Jae-Woung;Kim, Young-Nam;Yang, In-Young
    • Journal of Mechanical Science and Technology
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    • v.17 no.4
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    • pp.501-510
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    • 2003
  • The spot welded sections of automobiles such as the hat and double hat section members, absorb the most of the energy during the front-end collision. The purpose of this study was to analyze the collapse characteristics of spot welded section members with respect ttl the pitch or spot welds on flanges. through impact experiments and computation for para-closed sections and perfectly closed sections. The hat shaped section members were tested at the impact collapse velocities of 4.72 m/sec, 6.54 m/sec and 7.19 m/sec and double hat shaped section members were tested at the impact collapse velocities of 6.54 m/sec, 7.19 m/sec and 7.27 m/sec. A commercial LS-DYNA3D was used to simulate the collapse behavior of the hat and double hat shaped section members. The validity of the simulation was to be proved by comparing the simulation results and the experimental results.

Axial Impact Collapse Analysis of Spot Welded Hat and Double-hat Shaped Section Members Using an Explicit Finite Element Code

  • Cha, Cheon-Seok;Kim, Young-Nam;Kim, Sun-Kyu;Im, Kwang-Hee;Yang, In-Young
    • Journal of Mechanical Science and Technology
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    • v.16 no.1
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    • pp.32-38
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    • 2002
  • The purpose of this study is to analyze the collapse characteristics of widely used spot welded section members (hat and double hat section, nembers of vehicles) which possess the greatest energy absorbing capacity In an axial impact collapse. This study also suggests how the collapse load and deformation mode are obtained under impact. In the program system presented in this study, an explicit finite element code, LS-DY7A3D, is adopted for simulating complicated collapse behavior of the hat and double hat shaped section members with respect to section dimensions and spot weld pitches. Comparing the results with experiments, the simulation has been verified under a velocity of 7.19 m/sec (impact energy of 1034J)

Influence of Spot Weld Pitches on Collapse Characteristics of SCPI Vehicle Members (차체구조용 SCPI 강도부재의 점용접간격이 압궤특성에 미치는 영향)

  • 차천석;박제웅;양인영
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.78-78
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    • 2002
  • Front-side members are structures with the greatest energy absorbing capability in a front-end collision of vehicles. This paper was performed to analyze initial collapse characteristics of spot welded hat and double hat-shaped section members, which are basic shape of side members, on the shift of flange weld pitches. The impact collapse tests were carried out by using home-made vertical air compression impact testing machine, and impact velocity of hat-shaped section members is 4.17m/sec and that of double hat-shaped section members is 6.54m/sec. In impact collapse tests, the collapsed length of hat-shaped section members was about 45mm and that of double hat-shaped section members was about 50mm. In consideration of these condition, axial static collapse tests(0.00017m/sec) of hat and double hat-shaped section members were carried out by using UTM which was limited displacement, about 50mm. As the experimental results, to obtain the best initial collapse characteristics, it is important that stiffness of vehicle members increases as section shapes change and the progressively folding mode induces by flange welding pitch.

Influence of Spot Weld Pitches on Collapse Characteristics for SCP1 Vehicle Members (차체구조용 SCP1 강도부재의 점용접간격이 압궤특성에 미치는 영향)

  • 차천석;박제웅;양인영
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.802-808
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    • 2002
  • Front-side members are structures with the greatest energy absorbing capability in a front-end collision of vehicles. This paper was performed to analyze initial collapse characteristics of spot welded hat and double hat-shaped section members, which are basic shape of side members, on the shift of flange weld pitches. The impact collapse tests were carried out by using home-made vertical air compression impact testing machine, and impact velocity of hat-shaped section members is 4.17m/sec and that of double hat-shaped section members is 6.54m/sec. In impact collapse tests, the collapsed length of hat-shaped section members was about 45mm and that of double hat-shaped section members was about 50mm. In consideration of these condition, axial static collapse tests(0.00017m/sec) of hat and double hat-shaped section members were carried out by using UTM which was limited displacement, about 50mm. As the experimental results, to obtain the best initial collapse characteristics, it is important that stiffness of vehicle members increases as section shapes change and the progressively folding mode induces by flange welding pitch.

An Experimental Study on the Axial Impact Collapse Characteristics of Spot Welded Section Members

  • Cha, Cheon-Seok;Beak, Kyung-yun;Kim, Young-Nam;Park, Tae-Woung;Yang, In-Young
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.2
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    • pp.23-29
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    • 2003
  • The spot welded sections of automobiles (hat and double hat shaped sections) absorb most of the energy in a front-end collision. The target of this paper is to analyze the energy absorbing capacity of the structure against the front-end collision, and to obtain useful information for designing stage. Changed the spot welded pitches on the flanges, the hat and double hat shaped section members were tested on the axial collapse loads at various impact velocities. It was expected that para-closed sections would show collapse characteristics which be quite different from those of perfectly closed sections. Hat shaped section members were tested at the impact collapse velocities of 4.72m/sec, 6.54m/sec and 7.1m/sec and double hat shaped section members were tested at the impact collapse velocities of 6.54m/sec, 7.1 m/sec and 7.27m/sec.

A Study on Axial Collapse Characteristics of Spot Welded Double-Hat Shaped Section Members by FEM (FEM에 의한 점용접된 이중모자형 단면부재의 축방향 압궤특성에 관한 연구)

  • Cha, Cheon-Seok;Kim, Young-Nam;Yang, In-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.7
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    • pp.120-126
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    • 2001
  • The widely used spot welded section members of vehicles are structures which absorb most of the energy in a front-end collision. In front-end collision, sufficiently absorbed in the front parts, the impact energy does not reach the passengers. Simultaneously, the frame gets less damaged. This structures have to be very stiff, but collapse progressively to absorb the kinetic energy as expected. In the view of stiffness, the double-hat shaped section member is stiffer than the hat shaped section member. In progress of collapse, the hat shaped section member is collapsing progressively, but the double-hat shaped section member does not due to stiffness. An analysis on the hat shaped section member was previously completed. This paper concerns the collapse characteristic of the double-hat shaped section member. In the program system presented in this study, an explicit finite element code, LS-DYNA3D is adopted for simulating complicate collapse behavior of double hat shaped section members with respect to spot weld pitches. And comparing with the results from the quasi-static and impact experiment, the simulation has been verified.

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Axial Impact Collapse Analysis of Spot Welded Hat Shaped Section Members

  • Yang, In-Young;Cha, Cheon-Seok;Kang, Jong-Yup
    • Journal of Mechanical Science and Technology
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    • v.15 no.2
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    • pp.180-191
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    • 2001
  • The widely used spot welded sections of automobiles(hat and double hat shaped section members) absorb most of the energy in a front-end collision. The sections were tested with respect to axial static(10mm/min) and quasi-static(1000mm/min) loads. Based on these test results, specimens with various thicknesses, width ratios and spot weld pitches on the flange were tested at high impact velocity(7.19m/sec and 7.94m/sec) which simulates an actual car crash. Characteristics of collapse have been reviewed and structures for optimal energy absorbing capacity is suggested.

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Collapse Characteristics of vehicle Members with Spot Welded Hat-Shaped Section under Axial Compression (점용접된 차체구조용 모자형 단면부재의 축방향 압궤특성)

  • 차천석;양인영;전형주;김용우;김정호
    • Journal of the Korean Society of Safety
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    • v.15 no.4
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    • pp.20-27
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    • 2000
  • The hat shaped section members, spot welded strength resisting structures are the most energy absorbing ones of automobile components during the front-end collision. Under the static axial collapse load in velocity of 10mm/min and quasi-static collapse load in velocity of 1000mm/min, the collapse characteristics of the hat shaped section and double hat shaped section member have been analyzed by axial collapse tests with respect to the variations of spot weld pitches on the flanges. In addition, the quasi-static collapse simulations have been implemented in the same condition to the experiment's using FEM package, LS-DYNA3D. The simulated results have been verified in comparison with these from the quasi-static axial collapse tests. With the computational approaches the optimal energy absorbing structures can be suggested. Simulations are so helpful that the optimized data be supplied in designing vehicles in advance.

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Development of Vehicle Members with Spot Welded Thin-wall Section for Optimum Impart Characteristic -Based on Collapse Characteristics on the Varied Impact Velocities- (최적 충격특성에 갖는 차체구조용 점용접 박육단면부재의 개발 -충격속도변화에 따른 압궤특성을 중심으로-)

  • Yang, In-Yeong;Cha, Cheon-Seok;Gang, Jong-Yeop
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.7
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    • pp.1131-1138
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    • 2001
  • This paper concerns the crashworthiness of the widely used vehicle structure, the spot welded hat and double hat shaped section members, which are excellent on the point of the energy absorbing capacity and low production cost. The target of this paper is to analyze the energy absorption capacity of the structure against the front-end collision, and to obtain useful information for designing stage. Changing the spot weld pitches on the flanges, the hat and double hat shaped section members were tested on the axial collapse loads in impact velocities of 4.72m/sec, 6.54m/sec, 7.19m/sec and 7.27m/sec. To efficiently review the collapse characteristics of these sections, the simulation have been carried out using explicit FEM package, LS-DYNA3D. The solutions are compared with results from the impact collapse experiments.

Energy Absorption Characteristics of Side Member for Light-weight Having Various Stacking Condition and Shape of Section (경량화용 사이드부재의 적층구성 및 단면형상 변화에 따른 에너지흡수 특성)

  • Lee, Kil-Sung;Seo, Hyeon-Kyeong;Yang, In-Young;Sim, Jae-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6 s.261
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    • pp.671-678
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    • 2007
  • Front-side members of automobile, such as the hat shaped section members, are structures with the greatest energy absorbing capability in a front-end collision of vehicle. This paper was performed to analyze energy absorption characteristics of the hat shaped section members, which are basic shape of side member. The hat shaped section members consisted of the spot welded side member which was utilized to an actual vehicle and CFRP side member for lightweight of vehicle structural member. The members were tested under static axial loading by universal testing machine. Currently, stacking condition related to the collapse characteristics of composite materials is being considered as an issue fer the structural efficiency and safety of automobiles, aerospace vehicles, trains, ships even elevators during collision. So, energy absorption characteristics were analyzed according to stacking condition and shape of section and compared the results of spot welded side member with those of CFRP side member.