• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.68-75
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• 2000

The development of flexible automation in the manufacturing industry is concerned with production activities performed by unmanned machining system. A major topic relevant to metal-cutting operations is monitoring tool wear, which affects process efficiency and product quality, and implementing automatic tool replacements. In this paper, the measurement of the cutting force components has been found to provide a method for an in-process detection of tool wear. Cutting force components are divided into static and dynamic components in this paper, and the static components of cutting force have been used to detect flank wear. To eliminate the influence of variations in cutting conditions, tools, and workpiece materials, the force modeling is performed for various cutting conditions. The normalized force disparities are defined in this paper, and the relationships between normalized disparity and flank wear are established. Finally, Artificial neural network is used to learn these relationships and detect tool wear. According to the proposed method, the static force components could provide the effective means to detect flank wear for varying cutting conditions in turning operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.446-451
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• 2004

Over testing problems of satellites and theirs components have been issued due to their effects on satellite development cost and schedule. Force limited vibration tests were introduced as solution of the problems in 1980s. Over testing phenomena occurs due to the lack of similarity on interface impedance. Force limited vibration tests control interface force to simulate actual interface impedance. In this research, force limited vibration tests are applied on two satellites environmental tests. Force limits are calculated by using TDFS method and Semi-Empirical method. Four force sensors are employed to control interface force. The tests prove that force limited control reduced maximum interface acceleration in order of 3.

• Structural Engineering and Mechanics
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• v.68 no.2
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• pp.227-235
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• 2018

Cables are the main load-bearing members of prestressed structure and other tensegrity structures. Based on the static equilibrium principle, a new cable force identification method considering cable flexural rigidity is proposed. Its computational formula is derived and the strategy to solve its implicit formula is introduced as well. In order to improve the reliability and practicality of this method, the influence of the cable flexural rigidity on cable force identification accuracy is also investigated. Through cable force identification experiments, the relationships among certain parameters including jacking force, jacking displacement, initial cable force, and sectional area (flexural rigidity) are studied. The results show that the cable force calculated by the proposed method considering flexural rigidity is in good agreement with the finite element results and experimental results. The proposed method with high computational accuracy and resolution efficiency can avoid the influences of the boundary condition and the length of the cable on calculation accuracy and is proven to be conveniently applied to cable force identification in practice.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.153-155
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• 1994

Electric machines such as motors which have moving parts are desgined for producing mechanical force or torque. The accurate calculation of electromagnetic force and torque is important in the design these machines, Electromagnetic force calculation method using the results of Finite Element Method(FEM) has been presented variously in 2-D problems. Typically the Maxwell's Stress Tensor method and the method of virtual work are used. In the problems including current source, magnetic vector potentials(MVP) have mostly been used as an unknown variables for field analysis by numerical method; e, g. FEM. This paper, thus, introduces both methods using MVP in 3-D case. To verify the usefulness of presented methods, a solenoid model is chosen and analyzed by 3-D and axisymmetrical FEM. In each case, the calculated force are tabulated for several mesh schemes.

• Journal of Korean Association for Spatial Structures
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• v.11 no.4
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• pp.49-59
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• 2011

This paper presents a new numerical method by using Singular Value Decomposition force method for form-finding of tensegrity structures with constraints. In order to maintain the tensegrity structures stable, state of self-equilibrium stress should be introduced. The existing force method has some advantages about form-finding of tensegrity structures. However, this method has complex formulation. In force density method, dummy members are required for form -finding of tensegrity structures with constraints. Therefore this study proposes new force method using Singular value decomposition. The proposed method is both having easy basic consept and simple computation than existing force method. A numerical example is presented to demonstrate the efficiency and robustness in searching initial single integral feasible self-stress mode for tensegrity structures with constraints.

• Progress in Superconductivity and Cryogenics
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• v.1 no.2
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• pp.20-24
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• 1999

The study of HTS(High Temperature Superconducting) bulk in magnetic levitation system requires the calculation of currents distribution in HTS bulk is very important to determine this forces. We have made computer program to find this current distribution and levitation force. J-E relation in HTS bulk is extremely nonlinear, so iteration method must be used to determine the current distribution. We developed the method to determine the current distribution in the unifrom-field model and, using this method, calculated the levitation force in permanent-magnet-levitation model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1088-1094
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• 1997

An indirect cutting torque and cutting force estimation method is presented. This method uses a time-domain model between the spindle motor power, which calculated form measured spindle motor current and voltage. Spindle motor power is linear with cutting torque in this model. The cutting force is proportional to the cutting torque. Using trial cut, parameters are determined. Static sensitivity is suitable for various cutting conditions. The presented method is verified under several cutting tests on the CNC horizontal machining center.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.762-763
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• 2015

Magnetic coupling is used where required high reliability. because magnetic coupling's durability is stronger than mechanical coupling's durability. This paper shows the force characteristics of halbach array magnetized tubular type magnetic coupling using Analytical method. Analytical method was used, to find force characteristics. Finite element method (FEM) is used to validate force characteristics.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.159-164
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• 2000

In this paper, a computer simulation technique for the forging process having a floating die is presented. The penalty rigid-plastic finite element method is employed together with an iteratively force-balancing method, in which the convergence is achieved when the floating die part is in force equilibrium within the user-specified tolerance. The force balance is controled by adjusting the velocity of the floating die in an automatic manner. An application example of a three-stage cold forging process is given.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.155-160
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• 2006

Motor intentional disorders have been studied by visual examination methods such as cross-response task and Luria loop. To provide more analytical, quantitative information for motor intentional disorders, the present study developed a method which evaluates force control capabilities by the index finger. The assessment method analyzes the finger force control capabilities at four stages(initiation, development, maintenance, and termination) with NK Pinch-GripTM(force resolution= 0.098 N; temporal resolution=50Hz). By applying the assessment method, a patient(age=66) with callosal legion was compared with 6 healthy males(mean age=65.5, SD=2.8), showing significant but different decreases in force control capabilities depending on hand and response location. The assessment method would be of use to better understand various aspects of motor intentional disorders such as the effects of the disorders to the neurological network of the brain and severity assessment of the disorders.