• 대한기계학회논문집A
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• 제23권11호
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• pp.1871-1877
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• 1999

An optimal design method using a response surface method for dynamic characteristics of a washer is presented. The proposed method uses the design of experiment and a computer model is used for the experiment. The value of the cost function is estimated using a computer model for each case of the design variable variation. An orthogonal array is used to obtain best cases to be considered with minimum number of experimentation. Using these experimental values, optimal design is performed using a response surface method. The method used in this paper can be applied to any complicated mechanical systems that can be modelled and analyzed by a computer program. The method is applied to the design of dynamic characteristics of a washer.

• 한국생산제조학회지
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• 제7권3호
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• pp.110-117
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• 1998

A continuum-based configuration design sensitivity analysis method is developed for kinematically driven mechanical systems. The configuration design variable for mechanical systems is defined. The 3-1-3 Euler angle is employed as the orientation design variable. Kinematic admissibility conditions of configuration design change. Direct differentiation method is used to derive the governing equations of the design sensitivity. Numerical examples are presented to demonstrate the validity and effectiveness of the proposed method.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.25-30
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• 2006

This study is about an optimum design to improve the kinematic and compliance characteristics of a torsion-beam suspension system. The kinematic and compliance characteristics of an initial design of the suspension was obtained through a roll-mode analysis. The objective function was set to minimize within design constraints. The coordinates of the connecting point between the torsion-beam and the trailing arm were treated as design parameters. Since the torsion-beam suspension has large nonlinear effects due to kinematic and elastic motion, Genetic Algorithms were employed for the optimal design. The optimized results were verified through a double-lane change simulation using the full vehicle model.

• 한국생산제조학회지
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• 제26권1호
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• pp.130-136
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• 2017

The three-wheel pitching machine is a device that throws balls automatically instead of a pitcher and is used chiefly to train baseball players. The machine is abundantly used by people in indoor baseball grounds for baseball games. However, in Korea, foreign products are more popular because the efficiency of domestic products is poor as compared to that of the foreign ones. Therefore, a miniature pitching machine was manufactured to analyze and solve the problems of the existing machine. We added a feeder device to insert the balls in the machine and developed a smart phone application. The machine is easily controlled by a smart phone with bluetooth. While manufacturing the miniature, the existing problems were mitigated and the machine was redesigned for mass production. This study attempted to render the pitching machine more convenient and safer as a substitute for foreign pitching machines.

• 대한기계학회논문집A
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• 제37권9호
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• pp.1083-1091
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• 2013

미사일 설계에서는 매우 효율적이며 치명적인 극히 작은 탄두를 필요로 한다. 탄두에서 각 관통자의 관통성능과 관통자의 총 개수는 탄두 파괴성능에 영향을 미치는 주요 요인이다. 관통자 L/D 의 설계는 탄두의 공간과 중량에 직접적인 관련되어 있다. L 과 D 는 발사체의 길이와 직경이다. AUTODYN-3D code 가 관통자 관통의 영향을 연구하기 위해 사용되었다. 수치해석의 목적은 초기속도, 경사각도, 관통자의 L/D 와 같은 다양한 초기 조건 아래 초고속 충격에 의해 생성되는 관통자의 관통특성을 확인하는 것이다. $L/D{\leq}4$ 에서의 초기 충격속도 증가는 잔류질량과 잔류속도를 감소시킨다.

• 대한기계학회논문집A
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• 제37권11호
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• pp.1331-1337
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• 2013

본 논문에서는 반응표면법을 이용하여 양항력형 수직축 풍력발전기 블레이드의 구조 최적설계를 수행하였다. 선행연구의 구조해석 결과를 살펴보면 양항력형 수직축 풍력발전기 블레이드가 항복강도 이상의 응력이 발생하였으므로, 구조적 안전성을 확보하고자 최적화 기법을 적용한 구조설계를 재수행하였다. 이를 위해 먼저 블레이드에 발생하는 응력에 큰 영향을 주는 설계인자를 선정하였다. 이에 실험계획법 기반 반응표면법을 적용하였다. 목적함수 및 제한조건은 각각 중량 및 허용응력으로 설정하였다. 또한 중량 및 응력에 대한 설계인자의 영향을 평가하기 위한 민감도 해석을 수행하였다. 이러한 과정을 통해 양항력형 수직축 풍력발전기 블레이드의 구조 최적 설계를 수행하였다.

• 센서학회지
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• 제30권6호
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• pp.388-394
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• 2021

The conventional microelectromechanical system (MEMS) process has been used to fabricate sensors with high costs and high-volume productions. Emerging 3D printing can utilize various materials and quickly fabricate a product using low-cost equipment rather than traditional manufacturing processes. 3D printing also can produce the sensor using various materials and design its sensing structure with freely optimized shapes. Hence, 3D printing is expected to be a new technology that can produce sensors on-site and respond to on-demand demand by combining it with open platform technology. Therefore, this paper reviews three standard 3D printing technologies, such as Fused Deposition Modeling (FDM), Direct Ink Writing (DIW), and Digital Light Processing (DLP), which can apply to the sensor fabrication process. The review focuses on strain/load sensors having both sensing material features and structural features as well. NCPC (Nano Carbon Piezoresistive Composite) is also introduced as a promising 3D material due to its favorable sensing characteristics.

• 한국기계가공학회지
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• 제15권1호
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• pp.122-128
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• 2016

The purpose of this study was to develop improved strength of an arm and a boom on over-load environment, which causes damage in the initial design statement. To develop improved strength of an excavator front group, we calculated load conditions using the MATLAB program, and using these conditions, we performed a structural analysis of an excavator front group for the maximum digging force condition. Finally we performed a topology optimization to reduce weights of an arm and a boom, and we re-modeled an arm and a boom based on the topology design results and re-performed the structural analysis. The strength of the re-design is higher than the initial design but its weight is almost the same as the initial design.

• 한국생산제조학회지
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• 제26권1호
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• pp.100-107
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• 2017

3D printing is a technology that converts a computer-generated 3D model into a real object with additive manufacturing technology. A majority of 3D printing technologies uses one material, and this is considered a limitation. In this study, we developed a multi-material 3D printer by adopting dual resin vat and cleaning system with DLP (Digital Light Processing) 3D printing technology. The developed multi-material DLP 3D printer is composed of a manufacturing system, cleaning system, transporting system, and automatic resin recharging system. Various 3D structures were 3D printed with two materials, thus demonstrating the potential. Printing performance of the multi-material DLP 3D printer was studied by performing a comparative surface roughness test and tension test on specimens composed of one material as well as those composed of two materials.

• 한국생산제조학회지
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• 제26권1호
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• pp.108-113
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• 2017

In this paper, we proposed a three-dimensional(3D) scanning system based on laser vision technique for 3D model reconstruction. The proposed scanning system consists of line laser, camera, and turntable. We implemented the 3D scanning system using low quality elements. Although these are low quality elements, we reduced the 3D data reconstruction errors greatly using two methods. First, we developed a maximum brightness detection algorithm. This algorithm extracts the maximum brightness of the line laser to obtain the shape of the object. Second, we designed a new laser control device. This device helps to adjust the relative position of the turntable and line laser. These two methods greatly reduce the measuring noise. As a result, point cloud data can be obtained without complicated calculations.