• 한국기계가공학회지
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• 제12권2호
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• pp.91-99
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• 2013

Car cross beam made by aluminium for new car is designed for the substitution of steel and it can be verified the performance by computer simulations. The parts of car cross beam are designed to replace steel parts according to their manufacturing processes. At the first stage, the weight of the aluminium car cross beam can be reduced to 75% by comparing with that of steel car cross beam. But NVH performance of the aluminium car cross beam becomes slightly insufficient as compared with that of steel car cross beam. Taguchi method is adopted to optimize the design variables affecting NVH characteristics of car cross beam. New car cross beam is designed at the second stage by using these analysis results. Weight reduction can be obtained to 31.7% by design modification and material change of car cross beam in comparison with the original steel one. NVH characteristics of aluminium car cross beam become on an equal level with the steel car cross beam. By side impact analysis results, new car cross beam has higher performance as compared with the steel car cross beam.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.323-328
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• 2004

세계 컨테이너 무역 규모가 연간 $7\%$씩 증가함에 따라 항만 환경이 급격히 변화하고 있다. 이러한 항만의 변화에 성공적으로 대처하기 위해 차세대 항만하역시스템인 LMTT(Linear Motor-based Transfer Technology)의 연구가 진행되고 있다. LMTT용 Shuttle car의 frame부는 컨테이너를 지탱하는 outer beam, frame의 뼈대가 되는 inner beam, 두 beam을 연결시켜 보강하는 cross beam으로 구성되어 있으며, 본 연구에서는 이러한 frame은 설계하기 위하여 cross beam의 개수, 하중 재하 위치 및 inner beam의 위치에 따른 outer beam과의 거리 비 등이 frame의 강도 및 강성에 미치는 영향을 유한요소해석을 통하여 고찰하였다.

• 한국정밀공학회지
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• 제16권9호
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• pp.9-17
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• 1999

This investigation is the result of the structural analysis by finite element method for optimal design of the cross beam with circular holes of the electric car-body. in order to install the air pipe and electric wire pipe that correspond signal between electric machines for the control system and to reduce the weight of the electric car-body, several circular areas from a cross beam should be taken off. What we want to perform is the optimal design of a cross beam with circular holes to posses equal stress in comparison with no hole cross beam. first, no hole cross beam as basic modal be chosen, executing the analysis, reviewing the distribution of stress and displacement at each location. several parameter should be adopted from the cross beam geometry like the location and shape of the hole to affect the maximum stress and displacement. So the analysis was executed by finite element analysis for finding optimal design parameter to the change of the location and shape of the circular hole. finally, the optimal design of the cross beam with circular holes was obtained and the maximum equivalent stress was compared with no hole cross beam at each location.

• 한국항해항만학회지
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• 제29권1호
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• pp.77-82
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• 2005

컨테이너 무역 규모가 매년 증가함에 따라 항만 환경이 급격히 변화하고 있다. 이러한 항만의 변화에 성공적으로 대처하기 위해 차세대 항만하역시스템인 LMTT(Linear Motor-based Transfer Technology)의 연구가 진행되고 있다. LMTT용 셔틀 카의 프레임부는 내부 빔, 내부 빔, 크로스 빔으로 구성되어 있으며, 본 연구에서는 프레임을 설계하기 위하여 크로스 빔의 개수, 하중 재하 위치 및 내부 빔의 위치에 따른 외부 빔과의 거리비 등이 프레임의 강도 및 강성에 미치는 영향을 유한요소 해석을 통하여 하중이 외부 빔과 내부 빔에 동시에 작용하고 크로스 빔이 5개일 때가 최적의 조건이라는 결론을 얻을 수 있었다.

• 한국기계가공학회지
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• 제16권5호
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• pp.126-133
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• 2017

This report investigates the stress distribution according to the location and shape change of the circular hole for the lightweight design of the cross beam of a railway passenger car and studies the lightweight design. To design a lightweight cross beam with a circular hole, we selected the non-circular crossbeam as a basic model, examined the stress distribution and displacement by position and determined the location, shape, size and quantity of the hole for light weight. We analyzed the effects of the position and shape of the hole on the maximum equivalent stress and displacement. The influencing factors were set as the design parameters, and the stress value was examined according to the variation of each variable. By considering the stress value according to the change of each variable and selecting the design parameter with the narrowest scattering value of the stress at each position of the hollow cross beam with various hole positions and shapes, we studied a cross beam with a circle hole under identical load condition to have an equal stress distribution to that of a non-circular cross beam.

• International Journal of Advanced Culture Technology
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• 제8권2호
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• pp.159-164
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• 2020

The response analysis of frame structure with open section beams considering warping conditions and short duration load have been performed. When a beam of frame structure is subjected under torsional moment, the cross section will deform a warping as well as twist. For some thin-walled sections warping will be large, and accompanying warping restraint will induce axial and shear stresses and reduce the twist of beam which stiffens the beam in torsion. Because of impact or blast loads, the wave propagation effects become increasingly important as load duration decreases. This paper presents that a warping restraint in finite element model effects the behavior of beam deformation, dynamic mode shape and response analysis. The computer modelling of frame is discussed in linear beam element model and linear thin shell element model, also presents a correlation between computer predicted and actual experimental results for static deflection, natural frequencies and mode shapes of frame. A method to estimate the number of normal modes that are important is discussed.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.370-376
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• 2005

Magnesium alloys are becoming important material for light weight car body, due to their low specific density but high specific strength. However they have a poor weldability, caused high oxidization tendency and low vapor temperature. In this study, the welding performance of magnesium alloys was investigated for automobile application. The materials were rolled magnesium alloy sheet contains Al and Zn such as AZ3l , AZ6l and AZ9l. Three types of welding process were studied, that were GTAW, Laser beam welding and FSW. To evaluate the weldability, we examined the appearance of welding bead. Also we checked bead shape and internal defects such as crack and porosity on cross section of welding bead. The mechanical property was measured for welded specimen by tensile test. For determination of the strength change by welding process, the hardness profile across the welding center was measured. For the results, the tensile properties of welded specimen were decreased obviously on all welding process. For the fusion welding process such as GTAW and laser beam welding, the surface of the welding bead was covered with oxidized magnesium dust but it was removed by simple cleaning work as wipe-out with tissue. Also under cut, that caused vaporization of base metal was occurred. for the friction stir welding, there was no oxidation, under-cut or internal defects. However it had poor weld performance, the reason was cleavage fracture occurred at plastic deformation zone. For welding of magnesium alloy, the laser beam welding process was recommended.

• 소성∙가공
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• 제17권7호
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• pp.481-485
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• 2008

The subframe type rear suspension consisting of a side member and a front/rear cross member is widely used in a medium car and full car. In the small car case, the beam of tubular type without independent suspension system is used to reduce manufacturing cost. In this study, a subframe type rear suspension by hydroforming has been developed. In designing suspension, a driving stability and durability should be considered as an important factor for the performance improvement, respectively. Thus, we focus on increasing the stiffness of suspension and decreasing the maximum stress affecting a durability cycle life. Several optimization design techniques such as shape, size, and topology optimization are implemented to meet these requirements. The shapes of rear suspension obtained from optimization are formed by using hydroforming process. Through commercial software based on the finite element, the superiority of this design method is demonstrated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.399-400
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• 2006

LMTT(Linear Motor based Transfer Technology) is a new type of transfer system used in the maritime container terminal fur the port automation, and largely consists of a controller, shuttle car, and rail. The shuttle car is divided into the frame part, the driving part, and wheels. In order to design this system, various researches on each part of it must be conducted. In this study, we dealt with the optimum design for the frame part of the shuttle car designed from previous studies on the strength of the frame with respect to the number of cross beams to minimize the weight of the shuttle car and to satisfy design criteria of cargo-handling systems in container terminal. For the optimization of the frame, thicknesses of each beam were adopted as design variables, the weight of the frame as objective function, and stress and deflection per unit length as constraint condition.

• 한국기계가공학회지
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• 제11권6호
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• pp.82-87
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• 2012

The purpose of this study is to produce a side impact beam with high tensile steel using a roll forming process. The door side impact beam plays an important roll in a car because it protects passengers from external crash. The roll forming process is a continuous bending process wherein a long metal sheet is bended as it continuously passes several rolls. The characteristic of this study is that an impact beam is produced by a continuous process using a ultra high strength steel without a hardening heat treatment. A model was determined by analysing plasticity of a cross section shape considering high strength. Design parameters of the impact beam was determined by crash-analysing the model. Workpiece products were manufactured by designing dies for roll forming and setting them up in a following process line. Results of a bending test and a FEM analysis was considered and reviewed.