• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.115.4-115
• /
• 2002

The disc spinning machine is a specific production machine for discs of automobile. Using this machine, we could product superior wheels in hardness and strength to the press method and the machine made process time shorten by one-pass spinning. But, the spinning machine became huge because it needed maximum pressure during the process and this can badly affect the lifetime of components. In this paper, hydraulic control system was designed to make up for defects of spinning machine and to shorten overusing power. Experimental hydraulic control system was used to simulate the wheel disc spinning process and the control performance was evaluated for the required forces and positions.

• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.189-191
• /
• 2006

This paper analyzes effect of the spinning vehicle on the GPS signal. In rapid spinning vehicles such as missiles and space rockets, carrier phase and frequency depend on the roll rate of the vehicle. It induces phase and frequency modulation caused by the roll rate. The modulated phase and frequency increase dynamic stress error of the tracking loop. Even though higher order tracking loop can remove dynamic stress error, the dynamic stress error can not be remove in this case. In order to analyze the effect of the spinning vehicle on the GPS signal, the experiments are carried out. The experiment results show the modulation of the carrier frequency and phase caused by the roll rate of the spinning vehicle.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.126-129
• /
• 2008

In this study the aerodynamic characteristics of a canard-controlled missile with freely spinning tailfins were investigated by using a CFD code. The aerodynamic coefficients and roll-rate of freely spinning tailfins were calculated by an analysis of 6-DOF and the Euler code. Results were in good agreement with experimental data, and the roll-rates of freely spinning tailfins were also in good agreement with the experimental data for the roll and yaw canard control inputs. This indicates that the CFD Euler code can be applied to predict the canard-controlled missile with freely spinning tailfins.

• Journal of computational fluids engineering
• /
• v.14 no.4
• /
• pp.48-55
• /
• 2009

In this study, roll lock-in phenomena of freely spinning tailfins were investigated by a CFD code. To analyze a motion of freely spinning tailfins, this research use a Chimera method, an Euler code and a 6 degrees of freedom analysis. The numerical results of aerodynamic characteristics and roll rates of a canard-controlled missile with freely spinning tailfins show a good agreement with wind tunnel test results. Using the roll rates calculation result of freely spinning tailfins, roll lock-in phenomena is confirmed. Roll lock-in phenomena and Roll lock-in states can be predicted through effects of the induced vortex of the canards control and the analysis of the rolling moments of tailfins due to the bank angle.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.4
• /
• pp.89-95
• /
• 2005

This paper intends to identify experimentally the relationship between transverse vibration behavior of a spinning disk and high-frequency fluctuation in the driving torque. A testrig has been developed using a CD-ROM disk, a driving motor with torque-varying capability and a power transmission belt and a laser vibrometer was employed to measure the transverse vibration displacements of the disk for a certain range of the spinning speed. The results show that the spinning speed and the magnitude and frequency of the torque fluctuation affect the stability of the disk. In other word, the torque fluctuation causes the instability of the disk at several ranges of the spinning speed below the critical speed and its effects become larger as the disk spins faster or the magnitude of torque fluctuation becomes bigger. The experimental results are found to be in good agreement with analytical estimation.

• Structural Engineering and Mechanics
• /
• v.88 no.5
• /
• pp.405-417
• /
• 2023

This paper reveals theoretical research to the nonlinear dynamic response and initial geometric imperfections sensitivity of the spinning graphene platelets reinforced metal foams (GPLRMF) cylindrical shell under different boundary conditions in thermal environment. For the theoretical research, with the framework of von-Karman geometric nonlinearity, the GPLRMF cylindrical shell model which involves Coriolis acceleration and centrifugal acceleration caused by spinning motion is assumed to undergo large deformations. The coupled governing equations of motion are deduced using Euler-Lagrange principle and then solved by a combination of Galerkin's technique and modified Lindstedt Poincare (MLP) model. Furthermore, the impacts of a set of parameters including spinning velocity, initial geometric imperfections, temperature variation, weight fraction of GPLs, GPLs distribution pattern, porosity distribution pattern, porosity coefficient and external excitation amplitude on the nonlinear harmonic resonances of the spinning GPLRMF cylindrical shells are presented.

• Clean Technology
• /
• v.15 no.4
• /
• pp.245-252
• /
• 2009

Profiles development of melt spinning process of poly(lactic acid) (PLA) was simulated via a numerical method and the radial temperature distribution was calculated using finite difference method. The spinning speed ranged from 1 km/min to 5 km/min was analyzed and the effect of spinning conditions on the radial temperature distribution was investigated. At low spinning speed, the difference between PLA and poly(ethylene terephthalate) (PET) was relatively small. As the spinning speed increased, the difference in velocity profile became prominent. PLA showed a slower spinning speed than PET and solidified more slowly. The temperature difference between the core and surface of the PLA filament reached 4.6 K, which was less than that of PET filament with a difference of 10.4 K. The radial temperature difference increased with increasing the cooling-air velocity and the spinning temperature.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.5
• /
• pp.615-621
• /
• 2009

Since GPS receivers and INS algorithms do not work properly in the spinning vehicles due to change of the GPS signal and excess of the measurement limitation of the gyroscope, conventional GPS/INS integrated navigation systems do not provide accurate navigation outputs. This paper proposes a design method for GPS/INS integrated navigation systems of spinning vehicles. A special GPS receiver with a signal tracking loop for changed GPS signal caused by spinning and an INS with a roll estimation method are configured and the conventional integration filter is combined. The proposed method was verified through comparison of the navigation results. The result of the proposed method for the spinning vehicle was similar to that of the conventional navigation system without spinning.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.4 s.152
• /
• pp.607-614
• /
• 2006

This study was carried out to suggest the optimal spinning process condition which provides a proper range of tenacity and biodegradability as textile fibers. The effects of the melt spinning speed and heat treatment on the mechanical property and biodegradability of polylactic acid fiber were investigated. Polylactic acid(PLA) was spun in a high spinning speed of $2000{\sim}4000m/min$. Each specimen was heat-treated at $100^{\circ}C$ during 30min. Mechanical properties such as breaking stress and the degree of crystallinity were evaluated using WAXS. Biodegradability was estimated from the decrease of breaking stress, weight loss, and the degree of crystallinity after soil burial. Experimental results revealed that heat treated specimens showed higher breaking stress than untreated specimens, but the increase was not so high as was expected from the remarkable change of crystallinity by heat treatment. It was concluded that breaking stress was more influenced by spinning speed than heat treatment. In the soil burial test, however biodegradability calculated from weight loss was more influenced by heat treatment than spinning speed.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.11
• /
• pp.3252-3258
• /
• 2010

In this study, the effects of the various parameters of spinning and drawing processes on the properties of polyester full drawn yarn (FDY) prepared by steam processing during high-speed spinning were investigated using several techniques. The wet shrinkage ratio of the FDY was able to be manipulated by controlling the temperature and draw ratio. The FDY made using the steam high speed spinning technique exhibited identical properties (such as tenacity, elongation, and wet shrinkage ratio) to that of regular FDY, made using the spin-draw process. FDY prepared using the steam process during high-speed spinning showed excellent dyeability. The dye pick-up of the polyester yarn spun at high-speed spinning was found to be improved when dyed under an atmospheric pressure of $100^{\circ}C$. This result was the same as regular FDY dyed under a high pressure of $130^{\circ}C$.