• International Journal of Automotive Technology
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• v.4 no.3
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• pp.141-147
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• 2003

For improving high-safety, convenience, and ride comfort, the automotive design suffers from radical increase of the weight, the recycling-related rules, regulations on the waste gas, and environmental protection of the resources. Among them, it is well known that the weight increase is the most critical. Thus, in order to minimize the weight of the body-in-white that takes up 20-30% of the whole weight of the automobile, most automotive manufacturers have attempted to develop the aluminum intensive body-in-white using aluminum space frames. In this research, the crush test and simulation for aluminum extrusions are performed to evaluate the collapse characteristics of that light weighted material. Also. the same test and simulation was done for aluminum extrusions filled with structural foam. Then, these results are analyzed and compared. From these studies, the effectiveness of structural foam is evaluated in improving automotive crashworthiness. Finally, the design strategy and guideline of the structural form are suggested in order to improve the crashworthiness for aluminum space frame in the vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.155-160
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• 2003

For the weight reduction of vehicle body up to 20∼30% compared to the conventional monocoque steel body·.in-white, most automotive manufacturers have attempted to develop the aluminum intensive body-in-white using an aluminum space frame. In this paper, the crush tests and simulations for the aluminum extrusions filled with the structural from are performed to evaluate the collapse characteristics of that light weighted material. From these studies. the effectiveness of structural for is evaluated in improving automotive crashworthiness. In order to improve the improve energy absorption capability of the aluminum space frame body, safety design modifications are performed and analyzed based on the suggested collapse initiator concepts and on the application of the aluminum extrusions filled with structural foam. The effectiveness of these design concepts on the frontal and side impact characteristics of the aluminum intensive vehicle structure is investigated and summarized.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.175-180
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• 2008

Due to the global environment problems and the consumer's need for higher vehicle performance, it becomes very important for the global car makers to reduce vehicle weight. To reduce vehicle weight, many car makers have tried to use lightweight materials, for example, aluminum, magnesium, and plastics, for the vehicle structures and components. Especially, the ASF(aluminum space frame) is known for the excellent concept of the vehicle to satisfy structural rigidity, safety performance and weight reduction. In this research, the design of experiments and the multi-disciplinary optimization technique were utilized to meet the weight and structural rigidity target of the ASF. For the structural performance of the ASF, the locations and the size of aluminum extruded frames, aluminum cast nodes, and the aluminum sheets were optimized. As a result, the optimization design procedure has been set up to meet both structural and weight target of the ASF, and the assembled ASF showed good structural performance and weight reduction.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.363-369
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• 2000

Due to environmental problem for reduction in fuel consumption, vehicle emission and etc., many automotive makers are trying to reduce the weight of the vehicle. The most effective way to reduce the weight of vehicle is to use lighter materials, aluminum, plastics. Aluminum Space Frame has many advantages in weight reduction, body stiffness, ease of model change and so on. So, most of automotive manufacturers are attempting to develope Aluminum Space Frame body. For these reasons, we have developed Aluminum Intensive Vehicle based on steel monocoque body with Hyundai Motor Company. We achieved about 30% weight reduction, the stiffness of our model was higher than that of conventional steel monocoque body. In this paper, with optimization using FEM analysis, we could get more weight reduction and body stiffness increase. In the long run, we analyzed by means of simulation using PAM-CRASH to evaluate crush and crash characteristic of Aluminum Intensive Vehicle in comparison to steel monocoque automotive.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.635-641
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• 2005

This paper presents an ASF (Aluminum Space Frame) BIW (Body in White) optimal design, which minimizes weight and satisfies multidisciplinary constraints such as static stiffness, vibration characteristics, low-/high-speed crash, and occupant safety. As only one cycle CPU time for all the analyses is 12 hours, the ASF design having 11-design variable is a large scaled problem. In this study, ISCD-II and conservative least square fitting method were used for efficient RSM modeling. Likewise, the ALM method was used to solve the approximate optimization problem. The approximate optimum was sequentially added to remodel the RSM. The proposed optimization method uses only 20 analyses to solve the 11-design variable problem. Moreover, the optimal design can achieve $15.6\%$ weight reduction while satisfying all the multidisciplinary design constraints.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.216-233
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• 2002

Due to the environmental problems of fuel consumption and vehicle emission, etc., automotive makers are trying to reduce the weight of vehicles. The most effective way to reduce a vehicle weight is to use lighter materials, such as aluminum and plastics. Aluminum Intensive Vehicle(AIV) has many advantages in the aspects of weight reduction, body stiffness and model change. So, most of automotive manufacturers are attempting to develop AIV using Aluminum Space Frame(ASF). The weight of AIV can be generally reduced to about 30% than that of conventional steel vehicle without the loss of impact energy absorbing capability. And the body stiffness of AIV is higher than that of conventional steel monocoque body. In this study, Aluminum Intensive Vehicle is developed and analyzed on the basis of steel monocoque body. The energy absorbing characteristics of aluminum extrusion components are investigated from the test and simulation results. The crush and crash characteristics of AIV based on the FMVSS 208 regulations are evaluated in comparison with steel monocoque. Using these results, the design concepts of the effective energy absorbing members and the design guide line to improve crashworthiness for AIV are suggested.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.94-100
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• 2004

In order to improve the frontal crash performance of an Aluminum Space Frame Vehicle, this presents a systematic optimal design process to maximize the crush energy absorption capacity of side-members while satisfying the maximum displacement constraint. In this study, five design types are studied for selecting a good collapse initiator. Then, for the selected collapse initiator type, 7 design variables are defined to represent cross section shape, thickness and bead interval. The systematic optimization processor, R-INOPL uses DOE, RSM and numerical optimization techniques. R-INOPL uses only 14 analyses to solve the 7 design variable optimization problem the final design can improve 103.9% of the internal energy and reduce 13.9% of the maximum displacement.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.76-79
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• 2005

Bending deformation and energy absorption characteristics of aluminum-composite hybrid tube beams have been analyzed for improvement in the bending performance of aluminum space frame by using experimental tests combined with theoretical and finite element analyses. Hybrid tube beams composed of glass fabric/epoxy layer wrapped around on aluminum tube were made in autoclave with the recommended curing cycle. Basic properties of aluminum material used for initial input data of the finite element simulation and theoretical analysis were obtained from the true stress-true strain curve of specimen which had bean extracted from the Al tube beam. A modified theoretical model was developed to predict the resistance to the collapse of hybrid tube beams subjected to a bending load. Theoretical moment-rotation angle curves of hybrid tube beams were in good agreement with experimental ones, which was comparable to the results obtained from finite element simulation. Hybrid tube beams strengthened by composite layer on the whole web and flange showed an excellent bending strength and energy absorption capability.

• Journal of architectural history
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• v.9 no.3 s.24
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• pp.51-69
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• 2000

This study tries to analyze the development of architectural technologies appeared in several tall buildings and large spatial structures from 1955 to 1999 in Korea. We suppose that these buildings represent the development of technology in Korean modern architecture. By the detailed analysis of these buildings, we can arrive at a conclusion as such; During the years 1955-1999, there existed a great changement in the eighties. We can find this fact very well in the domain of structural system and curtain wall system. In large spatial structures, the structural-system of shell and steel truss dome was replaced by that of space frame, space truss and cable truss with membrane. In tall building, the structural system of rigid frame and shear wall was replaced by tubular system, core and outrigger system. Korean architects introduced the aluminum curtain wall in the sixties, but its low technological level caused many problems in reality. Therefore, precast concrete curtain wall appeared from seventies as the main method for an outer wall in tall building. With the augmentation of height after 1980, PC curtain wall was replaced by the aluminum curtain wall of unit type and structural glass wall system. These systems help to stress the transparency in a tall building.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.1-7
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• 2006

This paper presents an ASF (Aluminum Space Frame) BIW optimal design, which minimizes the weight and satisfies multi-disciplinary constraints such as the static stiffness, vibration characteristics, low-speed crash, high-speed crash and occupant protection. As only one cycle CPU time for all the analyses is 12 hours, the ASF design having 11-design variable is a large scaled problem. In this study, ISCD-II and conservative least square fitting method is used for efficient RSM modeling. Then, ALM method is used to solve the approximate optimization problem. The approximate optimum is sequentially added to remodel the RSM. The proposed optimization method used only 20 analyses to solve the 11-design variable design problem. Also, the optimal design can reduce the] $15\%$ of total weight while satisfying all of the multi-disciplinary design constraints.