• Transactions of the Korean Society of Automotive Engineers
• /
• 제10권4호
• /
• pp.141-148
• /
• 2002

Repair were made for front pillar, center pillar and side-step panel for lightweight vehicles with head-on and 40% off-set collision of 15 km/h in a RCAR standard. The salt dilution was sprayed and the compression tests were performed for vehicles with and without anti-corrosional treatment after repair. After 764 hours of salt-dilt sprayed test without using anti-corrosion, the mean penetration depth fur corrosion was shown to be 58% of the thickness. The resulyed decrease in bending stiffness by 10∼20% can cause reduction of the residual life and crash-absorption capability for damaged vehicles. The corrosoin safety tests showed that the anti-corrosional treatment should be made to improve the safety characteristics for a or damaged car.

• Proceedings of the KSME Conference
• /
• 대한기계학회 2001년도 추계학술대회논문집A
• /
• pp.772-777
• /
• 2001

The gas-assisted injection molding process is often perceived to be unpredictable, because of the extreme sensitivity of the gas. Since a slight change in design or process parameters can significantly change the resulting gas penetration, few designers and molders have the level of experience with the new gas-assisted injection molding process required for the development of new parts. This paper is concerned with the unified molding for a thick cosmetic chest by using gas-assisted injection molding. CAE analysis was carried out to design the part and the gas channel without inducing sink marks. And based on the part weight measurement, the processing parameters to control gas penetration percentage were chosen through the method of design of experiments. A thick cosmetic chest was successfully produced using the gas assist technology. The sink mark issue associated with the conventional injection molded parts was resolved. Weight savings and cycle-time reduction were also achieved.

• Proceedings of the KSME Conference
• /
• 대한기계학회 2001년도 추계학술대회논문집A
• /
• pp.67-72
• /
• 2001

The LBB behavior and the crack opening displacement after a crack penetrated wall thickness of statically indeterminate piping system were investigated in this study, compared with statically determinate piping system. The reduction of ultimate strength caused by a crack was relatively small in the statically indeterminate piping system. The statically indeterminate piping system has more safety margin for LBB behavior than the statically determinate piping system. The crack opening displacement could be evaluated by using the plastic rotation angle proposed to evaluate the crack opening displacement after crack penetration in pipe with a non-penetrating crack.

• Journal of Power System Engineering
• /
• 제12권5호
• /
• pp.14-19
• /
• 2008

In order to meet stringent future emission regulations, especially to reduce Particulate Matter (PM) and NOX, stoichiometric diesel combustion technology with a piezo group-hole nozzle injector is being researched for reduction harmful emissions. A new nozzle layout, namely a group-hole nozzle, which has one group of small orifices with a wide spray included angle was investigated to improve the efficiency of stoichiometric diesel combustion. From this point of view, the group-hole nozzle suggested by Dense Co. is an attractive candidate method applicable to stoichiometric diesel combustion. The group-hole nozzle concept is to reduce the injector nozzle hole diameters without sacrificing spray penetration by closely locating two holes. Experimental studies have proven that the spray from group-hole nozzles have similar spray penetration to that of a single hole with equivalent overall nozzle hole area, but the spray drop sizes (SMD) are reduced, aiding vaporization and mixing.

• Structural Engineering and Mechanics
• /
• 제51권3호
• /
• pp.403-412
• /
• 2014

In this paper, enhancement of corrosion and chloride resistance of high performance self compacting concrete (SCC) through incorporating nanosilica into the binder has been investigated. For this purpose, different mixtures were designed with different amounts of silica fume and nano silica admixtures. Different binder contents were also investigated to observe the binder content effect on the concrete properties. Corrosion behavior was evaluated by chloride penetration and resitivity tests. Water absorption and capillary absorption were also measured as other durability-related properties. The results showed that water absorption, capillary absorption and Cl ion percentage decreased rather significantly in the mixtures containing admixtures especially blend of silica fume and nano silica. By addition of the admixtures, resistivity of the SCC mixtures increased which can lead to reduction of corrosion probability.

• Transactions of Materials Processing
• /
• 제10권5호
• /
• pp.402-410
• /
• 2001

The gas-assisted injection molding process is often perceived to be unpredictable, because of the extreme sensitivity of the gas. Since a slight change in design or process parameters can significantly change the resulting gas penetration, few designers and molders have the level of experience with the new gas-assisted injection molding process required for the development of new parts. This paper is concerned with the unified molding for a thick cosmetic chest by using gas-assisted injection molding. CAE analysis was carried out to design the part and the gas channel without inducing sink marks. And based on the part weight measurement, the processing parameters to control gas penetration percentage were chosen through the method of design of experiments. A thick cosmetic chest was successfully produced using the gas assist technology. The sink mark issue associated with the conventional injection molded parts was resolved. Weight savings and cycle-time reduction were also achieved.

• Proceedings of the Korean Geotechical Society Conference
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.1678-1688
• /
• 2008

In this study, dredging reclamation ground were performed to evaluate the ground improvement and liquefaction reduction effect with the result that standard penetration test(SPT) and piezo penetration test(CPT) before and after of improvement. Especially, the estimate center of the pile and factor of liquefaction safety to the position of ground around with the pile presented improvement of compaction for improved compaction of dredging reclamation ground.

• Nuclear Engineering and Technology
• /
• 제53권3호
• /
• pp.932-941
• /
• 2021

This paper suggests a fracture simulation method for SFR metallic fuel pin under accident condition. Two major failure mechanisms - creep damage and eutectic penetration - are implemented in the suggested method. To simulate damaged element, stress-reduction concept to reduce stiffness of the damaged element is applied. Using the proposed method, the failure size of cladding can be predicted in addition to the failure time and failure site. To verify the suggested method, Whole-pin furnace (WPF) test and TREAT-M test conducted at Argonne National Laboratory (ANL) are simulated. In all cases, predicted results and experimental results are overall in good agreement. Based on the simulation result, the effect of eutectic-penetration depth representing failure behavior on failure size is studied.

• Journal of electromagnetic engineering and science
• /
• 제6권2호
• /
• pp.130-134
• /
• 2006

This paper presents the reduction characteristics of penetrated electromagnetic fields through a narrow slot in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the parallel wire or parallel plate connected on the slot. The magnitude of penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot. An integral equation for the aperture electric field on narrow slots is derived and solved by applying Galerkin's method of moments. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the parallel wire or parallel plate on the slot.

• Korean Chemical Engineering Research
• /
• 제60권4호
• /
• pp.557-563
• /
• 2022

In order to measure the allergen penetration of micropore fabrics, it is necessary to develop a convenient and appropriate experimental method for measuring a pore size of micropore fabrics. In this study, a simple and economical experimental apparatus was developed for the analysis of the pore size of micropore fabrics by measuring the weight reduction rate. In addition, the allergen blocking properties was evaluated by measuring the pore sizes of various fabrics. According to this study, the size of the pores of the microporous fabric could be obtained by measuring the weight reduction rates. In addition, higher weight reduction rate was obtained as the suction pressure passing through the particle permeation device decreased and the suction time was increased. It is expected that the developed experimental method and apparatus can be utilized as an experimental standard for quality control methods to verify the effectiveness of micropore fabrics used for house dust mite blocking bedding.