• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.566-572
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• 2013

In this study, a collision simulator for rolling stock that considers the plastic deformation of the car body and the dynamic characteristics of a coupler system was developed using Matlab/Simulink. Normally, a coupler system has functions for both connecting the individual car bodies and absorbing the impact energy. A coupler system is composed of a rubber buffer, hydraulic buffer, and deformation tube elements. The coupler system should protect the car body and prevent damage when the shunt speed is less than 10 km/h, which is the regulation speed based on the safety rule for rolling stock. However, if the shunt speed is greater than 10 km/h, a car body is plastically deformed. Therefore, the modeling of the plastic deformation of a car body should be included in a simulator. This collision simulator can provide the design parameters for a coupler system and car body.

• Journal of the Korean Society of Costume
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• v.53 no.1
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• pp.49-66
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• 2003

In the relationship between post-modern feminism and the body. the body of women, which has been taken as 'other' by dominant arguments, has escaped from the fixed idea at post-modern times and the post-modern feminists tried to escape from the taste of the times about body image that was prevalent in the former times.'The taste of the times' here means the fixed physical form of ideal women's body by the educational custom, and it includes the educational prescription which establishes the docile body of women. This kind of educational custom aims at the perfect and permanent restriction on size, shape, desire, attitude and movement as well as on the overall demeanor and each part of the body. And the custom produces 'dependent and trained'. that is, inferiorized women's body. Hence, this paper points out that the feminity as a fixed Physical form should be overcome in order to move forward, and as one part of the effort, it attempts to analyze the designs which deformed and distorted women's body in 1990s. This research indicates that the work, which tries to deviate the fantasized and casted women's mystery, has been closely connected with the expression of 'non-separate bodies' and 'irregular body shapes' in 1990s, which aims at escaping from the fixation of women's body Image. Therefore, it is concluded that the target design trend of this research, which expressed the deformation and perversion of the body, provides the anti-these against the ideal body image of women and the these of feminity. which have been reproduced in various methods and patterns throughout the public and the culture on the whole by expressing the refusal and deviation of the existing women's body image through the post-fixation of the body pattern.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.35-41
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• 2000

The crashworthiness of vehicles with finite element methods depends on the geometry modeling and the material properties. The vehicle body structures are generally composed of various members such as frames, stamped panels and deep-drawn parts from sheet metals. In order to ensure the impact characteristics of auto-body structures, the dynamic behavior of sheet metals must be examined to provide the appropriate constitutive relation. In this paper, high strain-rate tensile tests have been carried out with a tension type split Hopkinson bar apparatus specially designed for sheet metals. Experimental results from both static and dynamic tests with the tension split Hopkinson bar apparatus are interpolated to construct the Johnson-Cook and a modified Johnson-Cook equation as the constitutive relation, that should be applied to simulation of the dynamic behavior of auto-body structures. Simulation of auto-body structures has been carried out with an elasto-plastic finite element method with explicit time integration. The stress integration scheme with the plastic predictor-elastic corrector method is adopted in order to accurately keep track of the stress-strain relation for the rate-dependent model accurately. The crashworthiness of the structure with quasi-static constitutive relation is compared to the one with the rate-dependent constitutive model. Numerical simulation has been carried out for frontal frames and a hood of an automobile. Deformed shapes and the Impact energy absorption of the structure are investigated with the variation of the strain rate.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.86-87
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• 2003

Unstructured grid system is suitable for flows of complex geometries. For problems with moving boundary walls, the grid system must be changed and deformed with time if we use a body fitted grid system. In this paper, a new moving-grid finite-volume method on unstructured grid system is proposed and developed for unsteady compressible flows with shock waves. To assure geometric conservation laws on moving grid system, a control volume on the space-time unified domain is adopted for estimating numerical flux. The method is described and applied for two-dimensional flows.

• Journal of the Korea Computer Graphics Society
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• v.6 no.1
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• pp.11-17
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• 2000

We present collision-handling method that includes self-penetration in the case of the colliding between rigid and deformable objects. The collision between objects is detected through the overlap test to the hierarchical structures of the objects. For detecting the collision between the objects at in-between frame, we try overlap test using the structures of a dummy and the rigid objects in addition to the test between the rigid and deformable objects. The dummy object is made from the rigid objects moving direction. When collision occurs, a deformable object must be deformed, as the object doesn't permit penetration. Self-penetration may occur during the object is deformed. It is rapidly detected between the object and a dummy object of another type. The dummy object is made from the object's deformation area between two continuous frames. We constrain the object is deformed until it is self-contacted. Our method can be applied without concerning of the shape of a object.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.702-708
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• 2016

The torque converter is deformed according to the rotating speed and control pressure when engine power is transferred to the transmission. This deformation, which is called ballooning phenomenon, occurs mainly at the outer side by the centrifugal force of the automatic transmission fluid (ATF) and the control pressure from the valve body. Although the torque converter is slightly deformed when rotating, the ballooning phenomenon affects fluid performance, efficiency and durability. Thus, expansion characteristics analysis is important in determining torus size, control pressure and structure. In this paper, an analysis equation and FEM model was developed to investigate the expansion characteristics. Using this model, structural analysis was performed to investigate the relationships between deformation and the torus diameter. The results were confirmed by comparing with the test results.

• Transactions of Materials Processing
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• v.28 no.5
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• pp.266-274
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• 2019

Metal sealing is used to connecting the parts between valves and fuel pipes for a FCEV which utilizes hydrogen gas of 700 bar. Instead of general carbon steel, stainless steel is the primary material used to manufacture fuel pipes due to hydrogen embrittlement. The shape of deformation between metals is an important factor on the air-tightness of the metal to metal contact. Since the stainless steel pipe is hardened using the plastic forming during the tip shaping stage, this work hardening could have an effect on the deformed shape and characteristics of contact surfaces in fastening of pipes. In this paper, the deformation history of the pipe model was considered in order to analyze the hydrogen-tightness on the metal sealing part. The contact distance and the forward displacement for fastening were compared using experimental results and the simulation results. The simulation of the effect of material change on the fitting body demonstrated that the hardness or the strength of the formed tip of the pipe was designed to a proper valued level since the characteristics of the contact surface was exhibited better when the strength of the pipe was lower than that of the fitting body.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.369-372
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• 2006

Monolithic forging of cask is required continuously. Body-base monolithic forging of cask has advantage of an economical manufacturing process and better reliability for nuclear applications. Through the finite element analysis and parametric study of design variables, those are die angle, groove length and flange thickness, the optimal dimensions of preform and die sets are determined in order to develop a suitable forging process for body-base monolithic forging. To verify the result of finite element analysis, the physical model of 1/30 scale of actual product using plasticine was carried out. The result of this experiment, deformed shapes were very similar to the finite element analysis. As a result of this work, the special piercing method was developed using blank material consisting of a flange, groove and squared part.

• International Journal of Automotive Technology
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• v.4 no.3
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• pp.149-156
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• 2003

This paper is concerned with the energy absorption efficiency of auto-body side structures for the conventional steel and 60TRIP high strength steel. In order to evaluate the energy absorption efficiency, the dynamic crash analysis is carried out with the regulation of US-SINCAP. The analysis adopts the Johnson-Cook model for the dynamic material properties, which have been obtained from dynamic material tests. For the sake of the dynamic material properties, the analysis has been accurately peformed for the crashworthiness assesment. The analysis result provides deformed shapes, amounts of penetration and accelerations at several important points during crash. The result confirms that 60TRIP greatly improves the crashworthiness of the side members without sacrificing the weight and thus can be used for the light-weight design of an auto-body.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.132-138
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• 2005

In heavy industrial fields such as power plant and chemical plant, it is often necessary to restore damaged part of large machinery and structure which is installed in the hazard working place. In this paper, to estimate stress distribution which occurs during damage and restoration of cylindrical beam structure, the finite element technique has been used. A finite element model was verified by experiment for non deformed cylindrical beam structure. The displacements and elastic recovery have an excellent agreement between experiment and finite element analysis. The variations of stress distribution on deformation and restoration procedure for surfaces have been examined. The maximum von Mises stress appears in the surface for deformation and restoration procedure. In deformation procedure, the maximum stress occurs in the vicinity of support body. In restoration procedure, the maximum stress occurs in the vicinity of the fixing body. The fixing body allows avoiding stress concentration in adjacent support structure boundary.