• 한국금형공학회:학술대회논문집
• /
• 2008.06a
• /
• pp.129-133
• /
• 2008

As a rotating machine element, plastic gears are more and more widely used in such as industrial machine element, since plastic gear is lighter, higher wear-resistance, and higher vibration absorbing ability than metal gears. When operating plastic parts, tooth breakage and fatigue life shortened due to increasing number of applying load and tooth flank temperature rising, such that accuracy of plastic gears is divided from allowable range to cause vibration and noise. On this study, a internal plastic gears are developed which improved the filling balance molding process by a new injection mold structure. The new mold structure called HR3P(hot runner type 3plate mold). As the result from this studies, we obtained a very accurate roundness internal gears by using design of experiment.

• Structural Engineering and Mechanics
• /
• v.9 no.6
• /
• pp.569-588
• /
• 2000

The plastic collapse loads and their locations are predicted for a class of tapered, initially curved, and transversely corrugated cantilevered beams subjected to static tip loading. Results of both closed form and finite element solutions for several rigid perfectly plastic and elastic perfectly plastic beam models are evaluated. The governing equations are cast in nondimensional form for efficient studies of collapse load as it varies with beam geometry and the angle of the tip load. Static experiments for laboratory-scale configurations whose taper flared toward the tip, complemented the theory in that collapse occurred at points about 40% of the beams length from the fixed end. Experiments for low speed impact loading of these configurations showed that collapse occurred further from the fixed end, between the 61% and 71% points. The results may be applied to the design of safer highway guardrail terminal systems that collapse by design under vehicle impact.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.11
• /
• pp.2245-2252
• /
• 2002

Design sensitivity analysis scheme is proposed in an elasto -plastic finite element method with explicit time integration using a direct differentiation method. The direct differentiation is concerned with large deformation, the elasto-plastic constitutive relation, shell elements with reduced integration and the contact scheme. The design sensitivities with respect to the process parameter are calculated with the direct analytical differentiation of the governing equation. The sensitivity results obtained from the present theory are compared with that obtained by the finite difference method in a class of sheet metal forming problems such as hemi-spherical stretching and cylindrical cup deep-drawing. The result shows good agreement with the finite difference method and demonstrates that the preposed sensitivity calculation scheme is a pplicable in the complicated sheet metal forming analysis and design.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1193-1194
• /
• 2013

• Structural Engineering and Mechanics
• /
• v.63 no.1
• /
• pp.23-35
• /
• 2017

A nonlinear static procedure considering work-energy principle and global failure mechanism to estimate base shears of reinforced concrete (RC) frame-type structures is presented. The relative energy equation comprising of elastic vibrational energy, plastic strain energy and seismic input energy is obtained. The input energy is modified with a factor depending on damping ratio and ductility, and the energy that contributes to damage is obtained. The plastic energy is decreased with a factor to consider the reduced hysteretic behavior of RC members. Given the pre-selected failure mechanism, the modified energy balance equality is written using various approximations for modification factors of input energy and plastic energy in scientific literature. External work done by the design lateral forces distributed to story levels in accordance with Turkish Seismic Design Code is calculated considering the target plastic drift. Equating the plastic energy obtained from energy balance to external work done by the equivalent inertia forces considering, a total of 16 energy-based base shears for each frame are derived considering different combinations of modification factors. Ductility related parameters of modification factors are determined from pushover analysis. Relative input energy of multi degree of freedom (MDOF) system is approximated by using the modal-energy-decomposition approach. Energy-based design base shears are compared with those obtained from nonlinear time history (NLTH) analysis using recorded accelerograms. It is found that some of the energy-based base shears are in reasonable agreement with the mean base shear obtained from NLTH analysis.

• Journal of the Korean Society of Costume
• /
• v.52 no.3
• /
• pp.61-73
• /
• 2002

The purpose of this study lies in pursuing the unique plastic arts with the orchid motif which has the graceful colors and a variety of shapes beauty. Another aspect of this study intends to crease the modern costume design with the high added value by expressing the texture according to the material and tissue development for the continual improvement and promotion of the modern costume design in the handicraft art area. The results through the theoretical survey and the work production are as follows : First, the orchid which has the various shapes and colors provides the designers with the unique plastic arts and the possibilities for the unlimited expressions as the design motives. Second, we can see the creation of cubic plastic beauty in the moving line, as the material which has the flexible and brilliant shape fixation, used for expressing the shape beauty of the orchid. Third, this study reveals the extension of expression areas as a characteristic of the plastic arcs by applying handicraft techniques such as dyeing, corded tuck, flounce, crochet, weaving, beads embroidery, and art flower to the costumes for developing the unique material and texture. Finally, the possibility is suggested that the desires of the moderns searching for their own individualities can be met by creating the costumes with the added vague as the exposure of esthetic consciousness through the handicraft expression techniques.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.3
• /
• pp.208-212
• /
• 2015

This study will design the structural optimization of 21 W LED heat sink using the thermal conductive plastic materials. The thermal conductive plastic heat sink is inferior to aluminum heat sinks in thermal properties. This study will solve this problem using formability of thermal conductive plastic heat sink. A heat sink was optimized in terms of the number, and the thickness of fins and the base thickness of the heat sink, using the Heatsinkdesigner software. Also by using SolidWorks Flow simulation and thermal analysis software, the thermal characteristics of the heat sink were analyzed. As the result, the optimized heat sink has 17 fins, which are 1.5 mm thick and a 3.7 mm-thick base. The highest and the lowest temperature were $51.65^{\circ}C$ and $46.24^{\circ}C$ respectively. Based on these results, The thermal conductive plastic heat sink is considered possible to overcome heating problem when designing in complex structure.

• Korean Institute of Interior Design Journal
• /
• no.29
• /
• pp.77-85
• /
• 2001

The change of society causes the change of art necessarily. The experiments of plastic art which as been done by avant-garde movements at early 20th century have pursued ″Object drama″ consistently as trials of more or less abstract drama. As these plastic arts have used genre or media like circuses, sports, variate, films, screen play, newspapers and a quick method which had not been considered suitable for conventional aesthetic plastic arts, these arts looked provocative and, these provocative plastic arts have ignored universality shown in conventional arts and have caused extreme ″sensation″ accordingly. As a result, abstract art based on style which is against aestheticism and naturalism has been generalized. This style does not deny customary laws of art wholly but it requires new concept. Having ignored traditional styles, a new compositive and responsive way of composition which does not deviate from tradition has been pursued. A new and general understanding of arts which do not deny all conventionally-effective standards extremely has been developed. In this regard, this study analyzes characteristics of Bauhaus Theater which has tried to apply new technology engineering to plastic art as an integrated concept of art and technology amongst the directions of development of provocation, innovation and revolution in case of the plastic art of stage painting, and analyzes how this influences on modern painting in terms of avant-garde arts reviewing the meaning of this theory.

• Archives of Plastic Surgery
• /
• v.48 no.3
• /
• pp.261-268
• /
• 2021

Background Various methods have been described to close large meningomyelocele defects, but no technique has been proven superior to others. This study presents cases of meningomyelocele defect closure with a keystone-design perforator island flap. Methods A retrospective study was performed on 14 patients with meningomyelocele defects closed using various types of keystone flaps. Results The median age of the patients at surgery was 10.5 days (range, 1-369 days) and the average defect size was 22.5 cm² (range, 7.1-55.0 cm²). The average operative time for defect closure was 89.6 minutes (range, 45-120 minutes). Type IV bilateral keystone flaps were used for four defects, type IV unilateral flaps for six defects, type IIA flaps for two defects, and type III flaps for two defects. Conclusions All the defects healed completely with no major complications. The keystone-design perforator island flap is a reliable, easy, and fast technique to close large meningomyelocele defects.

• Archives of Plastic Surgery
• /
• v.40 no.2
• /
• pp.116-116
• /
• 2013