• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.684-687
• /
• 2002

The authors have developed two devices which cuts the spend fuel rod to an optimal size and extracts fuel pellet from the pieces of cut fuel rods. These devices are so important to reduce radioactive wastes that some advanced countries developed their own methods and devices. The authors have benchmarked from these methods and devices. For spent fuel rod cutting, the tube cutting method has been chosen. some mechanical properties of the fuel tube and pellet has been carefully considered for an optimal cutting size. For fuel pellet extraction, a mechanically extracting method has been adopted. The existing chemical method have turned out to be inappropriate because it produced large amount of radioactive wastes, in spite of its high fuel recovery characteristics. The developed method has an advantage that it can be applied to other fuel rods that have different shapes and sizes. The two devices are set up and operated in the hot cell where people can not go in, so that the devices have been designed to be controlled remotely and modulated for easy maintenance. And the performance of the devices has been tested by using simulated fuel rod. From the experimental results, the devices are supposed to be useful for reducing radioactive wastes.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.34 no.11
• /
• pp.45-54
• /
• 2018

The primary objective of this study is to develop a conceptual design of all-in-one attachment based steel pipe pile cutting robot that improves the conventional work in safety, quality, convenience and productivity. For this, the following research works are conducted sequentially; 1)literature review, 2)field investigation, 3)selection of element technology for conceptual design, 4)deduction of conceptual design and its work process, 5)technical feasibility analysis of the conceptual design and its work process. As a result, leveling laser and laser detector, plasma cutter, rotary grapple are selected as core technologies. Futhermore, a conceptual design and work process of an all-in-one attachment based steel pipe pile cutting robot are developed based on the core technologies. According to the technical feasibility analysis result, at least 76.8% of the respondents are selected positive answer about each device of the all-in-one attachment based steel pipe cutting robot. It is expected that the application range and impact on the construction industry will be enormous due to the increasing trend of the steel pipe pile market.

• Journal of Korean Society of Steel Construction
• /
• v.27 no.1
• /
• pp.77-85
• /
• 2015

This paper describes the development of force limiting device(FLD). The FLD could induce compressive yield before occurring elastic buckling for slender member under compressive load. Therefore, it might prevent reduction of load carrying capacity by elastic buckling and the structures with the devices would behave stable. A new type of FLD reduced cross area is proposed in this study different to existing studies like as out of plane type, slit type and folded plate type. The parameters of specimens are depth, width and number of cutting. The structural capacity and characteristics of proposed types were verified by experiment and FEM analysis. The FLD of cutting type is efficient in compressive member.

• Ecology and Resilient Infrastructure
• /
• v.7 no.4
• /
• pp.274-283
• /
• 2020

A large amount of fine dust is generated during the process of pavement cutting. Consequently, reducing the amount of fine dust generated during pavement cutting is crucial for the overall management of fine dust. Based on this premise, in this study, a conceptual model is proposed for a device that can be employed for recovering scattered dust generated at the site of pavement cutting. The economic feasibility associated with the incorporation of the proposed model was analyzed. Results obtained from the economic feasibility analysis of the proposed conceptual model indicate that the benefit ratio is 2.96, which is significantly higher than 1. The rate of return is found to be 62.78%, which significantly exceeds the minimum expected rate of return (i.e., 10%), as established on the basis of interviews conducted with companies that implement pavement cutting. Furthermore, the break-even point is found to be at approximately 21.6 months. Hence, the proposed pavement cutter, which features dust suction and a low noise level, is economically feasible.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.319-320
• /
• 2002

Numerical simulation of chip formation during high speed machining requires knowing the friction at tool/chip interface. This parameter is hardly identified and generally the loadings (temperature, force) during the identification are not similar to those encountered during machining. Thus, Coulomb friction identified with pin-on-disc device is often used to conduct numerical simulation. The used of this technique cannot leads to good numerical results of chip formation compared to the experimental tests especially in the case of low uncut chip thickness. In this contribution, we propose a new method to evaluate the friction at tool/chip interface. In fact several Coulomb friction parameters are identified corresponding to several parts of the cutting tool. Experimental tests have been conducted allowed us to determinate both the level and the distribution of the Coulomb friction. Experimental results are also compared to the results of orthogonal cutting simulation. We show that this technique allows predicting accuracy results of chip formation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1566-1570
• /
• 2005

The aspherical lenses are used as optical lens of HMD optical system. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, the diamond tool nose radius, the cutting speed, the feed rate, the depth of cut, and cutting fluid type are found. The demanded surface roughness 10 nm Ra, aspherical form error $1.0\;\mu{m}$ P-V for aspherical lens of optical data storage device are satisfied.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.1361-1366
• /
• 2009

This study is to see the internal flow for the plasma cutting fume collector. Plasma cutters are widely used in the canning industry and Fume cause the device because it will affect the performance of the design of dust collector. Therefore, to determine the distribution of the internal flow using CFD and Solver was used for calculated with commercial CFD code STAR-CCM+. The results show that design of chamber was incorrect after passed the filter for exhaust to the fan. And the location of the duct to the influx of dust collector and the design was incorrect. In addition, an array of filter was also inappropriate. As a result, present fume collector need to improvement.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.5
• /
• pp.401-406
• /
• 2013

Non-explosive shockless holding and release mechanism for a nano class small satellite application has been proposed and investigated. The great advantages of the mechanism are a much lower shock level and larger constraint force than the conventional mechanism using pyro and the heating wire cutting mechanism which has been generally applied to the cube satellite program. To investigate the effectiveness of the mechanism design, EM mechanism was developed and tested to verify the basic function of the mechanism. The test results indicate that the proposed mechanism is well functioning as the mechanism design intends.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.1
• /
• pp.123-130
• /
• 1996

The procedure on the design of a new tungsten cabide throw-away cutting tool system for deep grooving or cut-off machining is suggested. For relieving the maximum stress level at the corner radius of the blade holder, the finite element method is used. Also the pulling test device is proposed for measuring the holding force of the insert between the blade holder and the insert considering the materials in contact and configuration parameters of the holder.

• Journal of Biosystems Engineering
• /
• v.27 no.4
• /
• pp.301-310
• /
• 2002

With a purpose to manufacture an onion peeler, the root cutting equipment of the onion could be attached to a prototype onion peeler was developed. Before the experiment, the distribution of the dimensions of the Korean native onion were measured. And some types of the blades to cut and remove the root of the onion were designed and such characteristics as feasible revolution, conveying speed, and power requirement were investigated. From the result of the test, the selected one among the various cutters was the wing type blade with the round blade to cut out the root and with the vertical blade to cut a circular line. The optimum operating conditions of the wing type blade were revealed the revolution with no load was at 630 rpm, and the conveying speed was 0.08 m/s. Under these conditions, the maximum torque was 5.25 kg·m and the power requirement was 33 W, respectively.