기계안전분야 : 차체구조용 박육부재의 에너지흡수특성에 관한 실험적 연구

김정호,정종안,양인영 ( Jeong Ho Kim,Jong An Jung,In Young Yang ) 한국안전학회(구-한국산업안전학회) 1996 `96 추계학술연구발표회 Vol.- No.-

모자형 단면부재의 폭비와 플랜지 용접간격에 따른 압궤특성

차천석,강종엽,김영남,김정호,김선규,양인영,Cha, Cheon-Seok,Gang, Jong-Yeop,Kim, Yeong-Nam,Kim, Jeong-Ho,Kim, Seon-Gyu,Yang, In-Yeong 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.1

The fundamental and 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 on axial static(10mm/min) and quasi-static(1000mm/min) loads. Based on these test results, specimens with various thickness, shape and spot weld pitch on the flange have been tested with impact velocity(7.19m/sec) the same as a real life car clash. Characteristics of collapse have been reviewed and a structure of optimal energy absorbing capacity is suggested.

모자형 단면 점용접부재의 축방향 압궤특성에 관한 연구(Ⅰ)

차천석(Cheon Seok Cha),김정호(Jeong Ho Kim),양인영(In Young Yang) Korean Society for Precision Engineering 2000 한국정밀공학회지 Vol.17 No.3

AI/CFRP 혼성튜브의 적층각과 단면형상에 따른 축방향 압궤 특성

김선규,이길성,김성훈,차천석,김정호,양인영 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

알루미늄은 수송기계용 구조부재로 널리 쓰이고 있으며 복합재료가 이러한 수송기계용 구조부재로 쓰일 때 경량화와 많은 에너지 흡수 측면이 기대된다. 알루미늄 튜브는 CFRP(탄소 섬유 강화 복합재료)튜브에 비해 압궤하중은 낮지만 안정적인 소성변형에 의해 압궤되는 반면 CFRP 튜브는 알루미늄 튜브에 비해 압궤하중은 높지만 불안정한 취성파괴에 의해 압궤된다. 따라서 알루미늄과 CFRP의 조합은 안정적이며 뛰어난 에너지흡수를 기대할 수 있다. 본 연구에서는 알루미늄 원형과 사각튜브의 외측을 CFRP로 감싸 Al/CFRP 혼성튜브를 제작하여 축방향 압궤특성에 관하여 연구하였다. 알루미늄 튜브와 CFRP 튜브의 압궤특성을 기초로 하여, Al/CFRP 흔성튜브의 이방성 재료인 CFRP의 적층각과 단면형상의 변화를 주었다. 실험결과, Al/CFRP 흔성튜브는 알루미늄 튜브의 좌굴을 계기로 하여 CFRP 튜브의 불안정한 취성파괴의 단점을 보완하였다. 경량화 측면에서 단위 질량당 흡수에너지는 원형튜브가 사각튜브에 비해 약 45~70% 이상 높았으며 CFRP 적충각이 90˚일 때 가장높았다. Aluminum materials have been widely used in various vehicle structures. If composite materials are applied to vehicle structures, it is expected that not only the weight of the vehicle is decreased but also it absorb large amounts of energy. Aluminum tubes are lower than CFRP (Carbon Fiber Reinforced Plastics) tubes in the collapse load but absorb energy by stable plastic deformation. On the other hand, CFRP tubes are higher than aluminum tubes in the collapse load but absorb energy by unstable brittle failure. The combination of aluminum and composite may result in stable deformation and excellent energy absorption efficiency. The compressive axial collapse tests were performed to investigate collapse characteristics of Al/CFRP compound tubes which are aluminum tubes wrapped with CFRP outside the aluminum circular and square tubes. Based on collapse characteristics of aluminum tubes and CFRP tubes respectively, the axial collapse tests were performed for Al/CFRP compound tubes which have different CFRP orientation angles and cross-sections. Test results showed that Al/CFRP compound tubes supplemented the unstable brittle failure of CFRP tubes due to ductile nature of inner aluminum tubes. In the light-weight aspect, Absorbed energy per unit mass of circular tubes was higher than square tubes'. Absorbed energy per unit mass showed highest when CFRP orientation angle was 90 degrees.

강체 블록의 비선형 로킹진동특성에 관한 연구 : 미끄럼이 있는 경우 In the Case of Sliding Occurrence

김정호,김선규,양인영,정만용,나기대 한국산업안전학회 2000 한국안전학회지 Vol.15 No.1

This paper deals with rocking response behavior of rigid block structure subjected to horizontal excitation. A strict consideration of impact and sliding between the block and base is essential to investigate the rocking vibration characteristics because the rocking behavior were greatly influenced by the impact and sliding motion. Therefore, not only restitution coefficient between the block and base but also the energy dissipation rate which is associated with sliding motion, and the static and kinetic friction coefficient between those should be included in the modeling of rocking system. The analytic program was developed to be able to simulate the experimental responses of the block subjected to horizontal sinusoidal excitations. By using this program, rocking responses were numerically calculated by the nonlinear equations for rocking system. From the response simulation and rocking vibration experiment, the following results were obtained. The rocking responses are affected by the impact motion due to energy dissipation and friction and provide very complex behavior. The toppling condition of the block is also influenced by the impact motion and sliding motion.

경량화용 차체구조 박육부재의 에너지 흡수특성

김정호,양인영,윤규종 한국산업안전학회 1996 한국안전학회지 Vol.11 No.3

In this paper, collapse test of thin-walled structures, which are widely used in the vehicle members is carried out to observe the dependence of cross-sectional forms and materials on the absorbed energy in the viewpoint of crashworthiness. Also, specimens consist of two kinds (Al, CFRP) with various thickness. Comparisons of circular specimens are made to find characteristics of the different specimens on the absorption ability according to specimen thickness and materials.

점용접된 차체구조용 모자형 단면부재의 축방향 압궤특성

김용우,김정호,양인영,차천석,전형주 한국산업안전학회 2000 한국안전학회지 Vol.15 No.4

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 l0㎜/min and quasi-static collapse load in velocity of 1000㎜/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 those 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.

경량화용 박육부재의 형상비가 압궤특성에 미치는 영향

김정호,양인영,정종안 한국산업안전학회 1998 한국안전학회지 Vol.13 No.3

In this study, collapse test of thin-walled structure is performed under axially quasi-static and impact load in collapse characteristic to develop the optimum structural member for a light-oriented automobile. Furthermore, the energy-absorbing capacity is observed according to the variety of configuration(circular, square), aspect ratio in aluminum specimen to obtain basic data for the improved member of vehicle. In both quasi-static and impact collapse test, Al circular specimens collapse, in general, with axisymmetric mode in case of thin thickness while collapse with non-axisymmetric mode according to the thickness increase. For Al rectangular specimens, they collapse with axisymmetric mode in case of thin thickness, with mixed collapse mode according to the increase of thickness. In terms of initial max. load, A1 square specimen turns out the best member among specimens, and then Al square, circular and circular with large scaling ratio, respectively. In case of quasi-static compression test, the absorbed energy per unit volume and mass shows higher in A1 circular specimen, and then A1 square, circular with large scaling ratio, respectively, according to shape ratio the absorbed energy per unit volume and mass in case of max. impact compression load is higher than that of static load. But the absorbed energy per unit volume

충격하중을 받는 외팔보의 파괴패턴에 관한 연구

임광희,김정호,양인영 조선대학교 동력자원연구소 1994 動力資源硏究所誌 Vol.16 No.1

When the free end of the cantilever is subjected to an impact concentrated loading, the main conclusions obtained are as follows on the impact-fracture patterns: 1. In the case of impact velocity different, it is found that the impact of a steel ball causes cracks between a fixed end and impact point generated from the surface of specimen to the under surface except the particulary short beams. It shows that the generated cracks of impact point propagate to the under surface, drawing the curved lines. 2. In case the dropping height of a ball is constnat, and an impact velocity(V) is constant, the values C_1 (the length from an impact point to the generated crack point) is not effected by the specimen length l_1. 3. As the values of an impact velocity is higher, the length C_1 becomes short.