• The korean journal of orthodontics
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• v.26 no.3
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• pp.281-290
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• 1996

Determination of force system and prediction of side effects from unbent straight wire engaged in edgewise bracket is clinically very difficult because it is statically indeterminate system. This study is to develop a linear beam theory that explains the force system for straight wire engaged in edgewise bracket regardless of geometry(a/b), material, cross section of wire, and interbracket distance. 1. Formula for force system of bilateral fixed end beam was derived. 2. It is possible to calculate force system of each tooth engaged in continuous straight wire. 3. The possibility and location of permanent deformation can be predicted.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.198-208
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• 2001

In this paper, vibration suppression of an elastic beam fixed on a moving cart and carrying a fixed or moving mass is considered. A modified pulse sequence method with RIC(Robust Internal-loop Compensator) is proposed to suppress the single model residual vibration and to get accurate positioning of the beam-mass-cart system. The performance of the proposed input preshaping method is compared with that of the previous ones through simulations and experiments. Using the proposed method, it is able to suppress the initial vibration of the beam-mass-cart system carrying a concentrated mass. Accurate PTP(point-to-point) positioning of the moving mass without residual vibration is also obtained experimentally by modifying the proposed pulse sequence method. Finally, the proposed input preshaping method is applied successfully to the system to follow square trajectories of the moving mass without residual vibration.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.239-246
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• 2004

The fixed ends beam is analyzed by the s d 0 f system with the rigid-plastic model. And the safety criteria of the fixed ends beam to the Impulsive loads are established with the peak-load ratio to the static collapse load and impulse ratio to the ideal impulse producing the critical displacement. It is shown that the impulse and the peak-load of the impulsive loads are the important factors for the damage of the structures. It is also shown that the damage curves with the peak-load and impulse ratio are useful method to estimate the damage of the structures due to the emphasis on the equivalent dynamic loads rather than the equivalent static loads in the process of deriving the curve.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.402.1-402
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• 2002

A linearly tapered beam immersed partially in other material is considered and is modelled as a linearly tapered Bernoulli-Euler beam fixed at the bottom with a concentrated mass at the top. Its governing equations is derived and its free vibration analysis is performed for various boundary conditions. And the rotatory inertia of the eccentric lumped tip mass is considered. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.4
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• pp.372-376
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• 2012

The most common type of the piezoelectric energy harvester is the cantilevered beam since it is attached to the host structure and tuned to the frequency of the base excitation easily. However, the excessive strain at the fixed end of cantilevered beam causes some problems such as fatigue and durability. The use of higher vibration modes of the cantilevered beam may reduce the concentration of the strain at the fixed end since the strains of higher modes are distributed along the span. The results show that the use of high vibration mode is not efficient for power generation, but it reduces the excessive strain lever at typical region to prevent the failure by fatigue.

• Korean Journal of Materials Research
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• v.15 no.7
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• pp.458-464
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• 2005

In microelectronics packaging, the reliability of the metal/polymer interfaces is an important issue because the adhesion strength between dissimilar materials is often inherently poor. The modification of polymer surfaces by ion beam irradiation and rf plasma is commonly used to enhance the adhesion strength of the interface. T-peel strengths were measured using a Cu/polyimide system under varying $N_2^+$ ion beam irradiation conditions for pretreatment. The measured T-peel strength showed reversed camel back shape regarding the fixed metal-layer thickness, which was quite different from the results of the 90° peel test. The elementary analysis suggests that the variation of the T-peel strength is a combined outcome of the plastic bending work of the metal and polymer strips. The results indicate that the peel strength increases with $N_2^+$ ion beam irradiation energy at the fixed metal-layer thickness.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.42-46
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• 2005

In microelectronics packaging, the reliability of the metal/polymer interfaces is an important issue because the adhesion strength between dissimilar materials is often inherently poor. The modification of polymer sufaces by ion beam irradiation and rf plasma are commonly used to enhance the adhesion strength of the interface. T-peel strengths were measured using a Cu/polyimide system under varying $Ar^+$ ion beam irradiation pretreatment conditions. The measured T-peel strength showed reversed camel back shape regarding the fixed metal-layer thickness, which was quite different from the results of the $90^{\circ}$ peel test. The elementary analysis suggests that the variation of the T-peel strength is a combined outcome of the plastic bending work of the metal and polymer strips. The results indicate that the peel strength increases with $Ar^+$ ion beam irradiation energy at the fixed metal-layer thickness.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.437-442
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• 2014

Recently, the needs for the development and application of the micro marine robot (MMR) which has the advantages in terms of size and cost are increasing. However, the basis is very short in the domestic. While the obstacle avoidance sonar (OAS) which was optimized in terms of size and performance and has the ability of 4-directional detection was developed for the obstacle avoidance of the micro surface robot (MSR) fortunately, the problem that the detection performance is degraded according to the shape of the obstacle because of using the fixed sonar-beam with the limited beam width and detection range exists. To solve this problem, the MSR mechanism that implements the rotating sonar-beam using the spur gear and the servo motor is proposed in this paper. To verify the performance of the proposed mechanism, the wall-tracking of the MSR is considered and the comparison and analysis in term of detection performance and actuation command is performed with conventional fixed sonar-beam. The test results show the validity of the proposed mechanism.

• Computers and Concrete
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• v.33 no.3
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• pp.251-264
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• 2024

The present study pertains to the effects of variations in the location and size of drilled web openings on the behavior of fixed-fixed reinforced concrete (RC) beams. For this purpose, a reference bending beam with a transverse opening in each half span was tested to failure. Later, the same beam was modeled and analyzed with the help of finite element software using ABAQUS. Upon achieving close agreement between the experimental and numerical results, the location and size of the web opening were altered to uncover the effects of these factors on the shear strength and load-deflection behavior of RC beams. The experimental failure mode of the tested beam and the numerical results were also verified by theoretical calculations. In numerical analysis, when compared to the reference (D0) specimen, if the distance of the opening center from the support is 0 or h or 2h, reduction in load-bearing capacity of 1.5%-22.8% or 2.0%-11.3% or is 4.1%-40.7%. In other words, both the numerical analyses and theoretical calculations indicated that the beam behavior shifted from shear-controlled to flexure-controlled as the openings approached the supports. Furthermore, the deformation capacities, energy absorption values, and the ductilities of the beams with different opening diameters also increased with the decreasing distance of the opening from supports. Web compression failure was shown to be the predominant mode of failure of beams with large diameters due to the lack of sufficient material in the diagonal compression strut of the beam. The present study indicated that transverse openings with diameters, not exceeding about 1/3 of the entire beam depth, do not cause the premature shear failure of RC beams. Finally, shear damage should be prevented by placing special reinforcements in the areas where such gaps are opened.

• Journal of the Korean Mathematical Society
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• v.49 no.5
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• pp.947-964
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• 2012

In this paper, the memory type boundary stabilization for an Euler-Bernoulli beam with one end fixed and control at the other end is considered. We prove the existence of solutions using the Galerkin method and then investigate the exponential stability of solutions by using multiplier technique.