• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2603-2609
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• 2000

In this paper, track tension estimation methods are developed for tracked vehicles which are subject to various maneuvering tasks such as longitudinal driving on sloping and/or rough roads. The information of the track tension is very important for the tracked vehicles because the track tension is closely related to the maneuverability and the durability of the tracked vehicles. A modified 3 DOF dynamics model is derived for the tracked vehicles and is utilized for estimating the tractive force and track tension for the longitudinal driving case. The tension estimation performance of the proposed methods is verified through the simulation of the Multi-body Dynamics tool. The simulation results demonstrate the effectiveness of the proposed method under various maneuvering tasks of the tracked vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.3 s.96
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• pp.346-353
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• 2005

In this paper, the tension of assembly stay cable connected with massive anchorage block was calculated through back analysis of in-situ frequencies measured from a stadium structure. Direct approach to back analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method can search the optimal tension without regard to the initial ones and has a rapid convergence rate. To verify the reliability of back analysis, Tension formulas proposed by Zui et al. and Shimada were used. Tensions estimated by three methods are compared with the design tension, and are in a reasonable agreement with an error of more or less than 15%. Therefore, it is shown that back analysis applied in this paper is appropriate for estimation of cable tension force.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.214-221
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• 2003

Tension mask assembly is positioned right behind the glass-made front panels of CRT type display devices. The frame-supported thin metal sheet contains numerous slits, through which electron beams are focused to enhance definition. Pretension is imposed on the masks, especially for enlarged flat screens, in order to avoid vibration due to acoustic or mechanical impact. High temperature assembly process subsequent to pretensioning, however, degenerates the creep resistance of common mask materials, and if tensile stress is high enough, tension on the mask may be loosened substantially due to creep deformation. In this study, the assembly is modeled as a combined structure of beams and wire array, and a numerical simulation is attempted for pretensioning followed by high temperature process. According to a model study, small amount of creep strain is likely to be generated, but its adverse influence is not negligible. Some structural modification measures to reduce the creep-induced tension loosening are proposed and evaluated. Also, optimal configuration of frame structure is sought for, which maintains high tension of masks and minimizes the possible creep of frame simultaneously.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.4
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• pp.79-89
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• 1992

The behavior of belt tension in OHC drive timing belt system was investigated analytically and experimentally for (1)fixed and (2)automatic tensioner. From the numerical results it was found that the automatic tensioner makes the belt tension larger than those of the fixed tensioner. When the initial belt tension decreased due to the belt elongation, the belt tension of the fixed tensioner could decrease to near zero while the belt tension for the automatic tensioner maintained above zero by the tensioner spring. The mean valve and the difference between the maximum and the minimum belt tension for the automatic tensioner increased compared with those of the fixed tensioner. Also, the numerical results for a hydraulic tensioner showed that the hydraulic tensioner has the good parts of both tensioners; i.e., thesmaller amplitude in belt tension and the higher mean tension. Experimental results for the automatic and fixed tensioner of the OHC timing belt system were in agreement with the theoretical results.

• Fibers and Polymers
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• v.3 no.2
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• pp.80-84
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• 2002

Tension control is an important factor in producing high quality knitted products and in maintaining good processing condition. Yarn tension during knitting is subject to be affected from many elements of the machine and process parameters. Several factors including yam feeding speed, feeding angle, and needle gauge that are considered to influence on the tension variation were investigated. Yam feeding speed did not show high contribution to the tension variation but feeding angle of yam did show high correlation with the tension. No or negative correlation of the tension with needle gauge was found from the results. In order to keep well-determined process condition in the knitting manufacturing, it is strongly suggested that all knitting elements and parameters should be in the integrated control circumstance.

• Journal of Power System Engineering
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• v.12 no.1
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• pp.72-79
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• 2008

This paper designs a looper-tension controller for mass-flow stabilization in hot strip finishing mills. By Newton's 2nd law and Hooke's law, nonlinear dynamic equations on the looper-tension system are firstly derived, and linearized by a linearization algorithm using a Taylor's series expansion. Moreover, a tension calculation model is obtained from the nonlinear dynamic equations which is called as a soft sensor of strip tension between two neighboring stands. Next, a looper-tension servo controller is designed by an ILQ(Inverse Linear Quadratic optimal control) algorithm, and it is combined with a minimal disturbance observer which to attenuate speed disturbances by AGC and operator interventions, etc.. Finally, it is shown from by a computer simulation that the proposed ILQ controller with a disturbance observer is very effective in stabilizing the strip mass-flow under some disturbances, moreover it has a good command following performance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.9
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• pp.503-509
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• 1999

This paper proposes a new speed and tension control algorithm for multi-span continuous strip processing line. In this algorithm the speed reference of each roll is adjusted to make the output force follow the load balance reference using an outer loop controller in cascade. Using the information of the output force of the adjacent roll, it is shown that the strip tension between two rolls can be controlled as the desired value without tension sensor. An experimental set-up which consists of 4 driven and 3 measuring rolls is designed and built for the multi-span speed and tension control. The experimental result reveals conspicuous improvement of tension control performance by the proposed algorithm comparing to the conventional tension feedback controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.435-440
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• 2004

In this paper, the tension of assembly stay cable connected with massive anchorage block was calculated through back analysis of in-situ frequencies measured from a stadium structure. Direct approach to back analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method can search the optimal tension without regard to the initial ones and has a rapid convergence rate. To verify the reliability of back analysis, Tension formulas proposed by Zui et al. and Shimada were used. Tensions estimated by three methods are compared with the design tension, and are in a reasonable agreement with an error of more or less than 15%. Therefore, it is shown that back analysis applied in this paper is appropriate for estimation of cable tension force.

• Structural Engineering and Mechanics
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• v.34 no.2
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• pp.189-211
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• 2010

The behaviour of a reinforced concrete tension member is governed by the contribution of concrete between cracks, tension stiffening effect. Under highly repeated loading, this contribution is progressively reduced and the member response approximates that given by the fully cracked member. When focusing on the unloaded state, experiments show deformations larger than those of the naked reinforcement. This has been referred to as negative tension stiffening and is due to the fact that concrete carries compressive stresses along the crack spacing, even thought the tie is subjected to an external tensile force. In this paper a cycle-dependent approach is presented to reproduce the behaviour of the axially loaded tension member, paying attention to the negative tension stiffening contribution. The interaction of cyclic bond degradation and time-dependent effects of concrete is investigated. Finally, some practical diagrams are given to account for the negative tension stiffening effect in reinforced concrete elements.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.4_2
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• pp.869-876
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• 2024

In this paper, a tension control system is developed to control temperature deviation due to tension fluctuations in a continuous sterilizer. The fluid flow in the sterilizer is expressed by conservation equations, and the tension control system is modeled using the mass flow rate between two transfer rolls. We analyze the elastic and shear deformation of the internal chain in the sterilizer. As a result of the tension control simulation, it is seen that the tension is recovered about 0.3 sec after the tension deviation. Using a experimental test, we show that the average temperature is similar, but the temperature deviation is improved from 3.1℃ to 1.2℃.