• 오토저널
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• 제12권3호
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• pp.9-20
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• 1990

The speed ratio-torque load-axial force characteristics of a rubber V-belt (RVB) and a metal V-belt (MVB) CVT are investigated and their performances are compared. It is found that power is transmitted by tension difference in RVB, and by thrust difference in MVB. The nondimensional equations for speed ratio-torque load-axial force of RVB are exactly same as those of MVB. However, actual characteristics of axial forces of RVB and MVB are different depending on their power transmission methods. The torque capacity of MVB is 5-6 times higher than that of RVB due to MVB's higher strength, even if the required axial force of MVB CVT control is 3-4 times higher than that of RVB.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.159-166
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• 2000

A new method of estimating axial nail force is proposed. An instrumented soil nail wall is selected to investigate the effectiveness of the new proposed method. The new method includes effect of creep and age of cement grout surrounding the steel bar, The new method also considers cracks in the grout generated during and after the end of the wall construction. It is found from this study that a reduced grout stiffness due to creep with age and crack of the grout must be considered for estimating correct axial nail forces. The reduced grout stiffness is considered also providing significant part of axial nail load compared to that of steel bar.

• 한국농공학회지
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• 제34권1호
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• pp.57-65
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• 1992

The main purpose of this paper is to present both the natural frequencies and mode shapes of tapered beams under tensile axial force. The differential equation governing planar free vibration for tapered beams under tensile axial force is derived as nondimensional form. The three kinds of cross sectional shape are considered in differential equation. The Runge-Kutta method and Determinant Search method are used to perform the integration of the differential equation and to determine the natural frequencies, respectively. The hinged-hinged, hinged-clamped, clamped-clamped and constraints are applied in numerical examples. The lowest four nondimensional natural frequencies are reported as the function of nondimensional tensile axial force. The fundamental natural frequencies are presented when section ratios and nondimensional axial forces are varied. The effects of cross sectional shapes are reported and some typical mode shapes are also presented.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.173-179
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• 2001

The torsional or axial critical vibration of the order coinciding with the number of propeller blades is simultaneously excited by the harmonic tangential or radial forces acting on the crank shaft and by the harmonic of the same order from the propeller. The exciting torque of propeller is relatively small comparing with that of crank side, but the exciting force of propeller rather larger than that of crank shaft. With this situation, the exciting force of propeller cannot neglect if the axial vibration of propulsion shafting is calculated. With the propeller in its optimal angular position, i.e. its excitation effect opposed to that of the engine, the stresses at the critical revolution will largely cancel themselves out. In this paper, a method of optimizing the angular propeller position with regard to torsional and axial vibration is studied. The optimal relative angle is determined theoretically by calculation results of coupled torsional-axial vibration.

• Advances in concrete construction
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• 제13권3호
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• pp.255-264
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• 2022

Vibration is expected to occur in microtubules as tubular heterodimers. They oscillate like electric dipoles. Several research studies have estimated a frequency of vibration using the orthotropic model, a beam or rod like models and shell models, considering the surface forces. The effects of body forces on the dynamics of the microtubules were not yet taken into account. This study seeks to capture the body force effects on the vibration modes generated and on the corresponding frequency for microtubules. An orthotropic elastic shell model for the structural details of microtubules is used for the analysis. The tests are conducted out for microtubules, exposed to electro-magnetic and gravitational forces, the transverse vibration, radial mode vibration, and axial mode of vibration have accomplished. We therefore, evaluate and compare microtubules' frequencies with prior results of vibration frequency without the effects of body force.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.129-136
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• 1999

The use of strut preloading method is gradually increasing in braced excavations in Korea. And it is necessary to analyse the effects of strut preloading on the wall deflection, bending moment and strut axial force etc. In this study, by using the analysis method of beams on elasto-plastic foundations, parametric studies of correlation between preloading and earth retaining structures in sandy soils were peformed in strut preloading application. As results, about 50% of design strut load was effective as a preloading force in considering the displacement and member forces of structures. And at least the effective stiffness of strut should be over 25% of the ideal value in order to restrain the excessive increase of wall deflection and bending moments. In order to protect excessive movements in braced excavation, to preload the strut was rather effective way than to increase the stiffness of strut and braced wall, but the excessive axial force of strut should be checked simultaneously.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.454-460
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• 1998

The vibration behavior of fuel rods has been analyzed by FEM in consideration of axial force and support spring constants. The axial compression force on the fuel rod in reactor decreases with the fuel rod burnup, and its decrease makes the natural frequencies of fuel rod considerably increase. The change of support spring constant can contribute to the remarkable change of the mode shapes, but not greatly to the natural frequencies. The reaction forces of support springs are obtained from normalizing the lst mode with the max. 0.2 mm displacement. The calculated reaction forces are larger than the previous results obtained by disregarding the deflections of the support springs.

• Structural Engineering and Mechanics
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• 제4권3호
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• pp.330-344
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• 1996

A model of a cable comprising interacting wires with dry friction forces at the interfaces is subjected to a quasi-static cyclic loading. The first cycle of this process, comprising of axial loading, unloading and reloading is investigated analytically. Explicit load-elongation relationships are obtained for all of the above phases of the cycle. An expression for the hysteretic losses is also obtained in an explicit form. It is shown that losses are proportional to the third power of the amplitude of the oscillating axial force, and are in inverse proportion to the interwire friction forces. The results obtained are used to introduce a model of a cable as a solid rod with an equivalent stiffness and damping properties of the rod material. It is shown that the stiffness of the equivalent rod is weakly nonlinear, whereas the viscous damping coefficient is proportional to the amplitude of the oscillation. Some numerical results illustrating the effect of cable parameters on the losses are given.

• 한국해양공학회지
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• 제12권3호통권29호
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• pp.9-18
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• 1998

An improved evaluation method of load-carrying capacity for the large-scaled offshore structures, which subjected to the axial force and bending moments simultaneously at the piles, was suggested with reliability analysis and advanced working stress method. Reliability analysis requires the fracture probability and safety factor(${beta}$) for each of forces and the load-carrying capacity due to combined action of axial force and bending moments from $P_n - {beta}$ Curve. The combined equation due to those forces, which suggested by the Korean Specification for the marine structure, was derived for the advanced working stress method and applied to evaluate the load-carrying capacity of jacket-type dolphin piers.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.993-1000
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• 2006

Practical stability design method of main members of cable-stayed bridges is proposed and discussed through a design example. For this purpose, initial tensions of stay cables and axial forces of main members are firstly determined using initial shaping analysis of bridges under dead loads. And then the effective buckling length using system elastic/inelastic buckling analysis and bending moments considering $P-{\delta}-{\Delta}$ effect by second-order elastic analysis are calculated for main girder and pylon members subjected to both axial forces and moments, respectively. Particularly, load combinations of dead and live loads, in which maximum load effects due to live loads are obtained, are taken into account and effects of live loads on effective buckling lengths are investigated.