• The KSFM Journal of Fluid Machinery
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• v.5 no.2 s.15
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• pp.43-49
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• 2002

In this paper, the steady-state performances analysis of a tilting pad gas bearing(TPGB) we analyzed by using finite element method for compressible Reynolds' equation. TPGB is used in a high-expansion-ratio expander running at a speed of 230,000 rpm. In order to solve the nonlinear finite element equations, the Newton-Raphson method is applied. The variations of the loading capacity, friction force and tilting angle of a single pad v.s. eccentricity direction of eccentricity and bearing number are investigated. The condition for the equilibrium of a pad, which is important for safe working of the bearing, is stated. The performances of the three pad bearing such as loading capacity, friction moment are predicted.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.751-755
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• 2007

The purpose of this study is to find the optimization processing on expanded tube using Taguchi method which was generally used to analyze the effects of various control factors. Mini-Tab is a good for program that is making a selection using Taguchi method. The results of experimental test and analysis are as follows. Optimization processing on a expanded tube is dependent on lubrication condition. The slight eccentricity of expanded tube was obtained a good results on the expanded tube. When expending processing on the expanded tube was performed, the test specimens were almost unaffected by changing pressure loading. The tendencies of test results were related to lubrication condition and eccentricity in expending processing. As a result, a proper lubrication condition and eccentricity in the step of design will improve the optimization processing of expanded tube.

• Advances in concrete construction
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• v.10 no.2
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• pp.151-159
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• 2020

An experimental study on the stress-strain relation of PVC-CFRP confined reinforced concrete columns subjected to eccentric compression was carried out. Two parameters, such as the CFRP strips spacing and eccentricity of axial load, were considered. The experimental results showed that all specimens failed by compressive yield of longitudinal steel bar and rupture of CFRP strips. The bearing capacity of specimen decreases as the eccentricity or the CFRP strips spacing increases. The stress-strain relation of specimens undergoes two stages: parabolic and linear stages. In the parabolic stage, the slope of stress-strain curve decreases gradually as the eccentricity of axial loading increases while the CFRP strips spacing has little effect on the slope of stress-strain curve. For the linear stage, the slope of stress-strain curve decreases as the eccentricity of axial load or the CFRP strips spacing increases. A model for predicting the stress-strain relation of columns under eccentric compression is proposed and it agrees well with various test data.

• Structural Engineering and Mechanics
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• v.9 no.6
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• pp.615-636
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• 2000

Some elevated water tanks have failed due to torsional vibrations in past earthquakes. The overall axisymmetric structural geometry and mass distribution of such structures may leave only a small accidental eccentricity between centre of stiffness and centre of mass. Such a small accidental eccentricity is not expected to cause a torsional failure. This paper studies the possibility of amplified torsional behaviour of elevated water tanks due to such small accidental eccentricity in the elastic as well as inelastic range; using two simple idealized systems with two coupled lateral-torsional degrees of freedom. The systems are capable of retaining the characteristics of two extreme categories of water tanks namely, a) tanks on staging with less number of columns and panels and b) tanks on staging with large number of columns and panels. The study shows that the presence of a small eccentricity may lead to large displacement of the staging edge in the elastic range, if the torsional-to-lateral time period ratio $({\tau})$ of the elevated tanks lies within a critical range of 0.7< ${\tau}$ <1.25. Inelastic behaviour study reveals that such excessive displacement in some of the reinforced concrete staging elements may cause unsymmetric yielding. This may lead to progressive strength deterioration through successive yielding in same elements under cyclic loading during earthquakes. Such localized strength drop progressively develop large strength eccentricity resulting in large localized inelastic displacement and ductility demand, leading to failure. So, elevated water tanks should have ${\tau}$ outside the said critical range to avoid amplified torsional response. The tanks supported on staging with less number of columns and panels are found to have greater torsional vulnerability. Tanks located near faults seem to have torsional vulnerability for large ${\tau}$.

• Steel and Composite Structures
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• v.5 no.1
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• pp.35-47
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• 2005

This paper presents the results of a series of tests carried out on hollow and concrete-filled coldformed steel sections subjected to axial and bending forces. The effects of eccentricity ratio and strength of in-fill on the behaviour of these sections were studied. A total of forty-eight medium sized columns and six beams were tested to failure. Extensive measurements of material properties, strains, axial shortening and lateral deflection were carried out. Interaction of local and overall buckling was observed in the tests. Failure mode observations were local buckling coupled with overall buckling. A description of the specially fabricated end fixtures for applying eccentric loading to the columns and to simulate pinned end condition is also presented. The experimental results of hollow columns are compared with the existing Indian, British and American codes of practice and the results of concrete-filled columns are compared with EC4 recommendations. It is seen that in the case of hollow columns predictions based on British and American codes of practice and in the case of concrete-filled columns predictions based on EC4 recommendations agree reasonably well with the experimental results. From the experiments it is seen that the provision of in-fill substantially increases the ultimate load carrying capacity of the order of one and a half to two times and the increase in strength of the in-filled concrete from a low grade concrete of compressive strength 24.94 MPa to a high grade concrete of compressive strength 33.26 MPa increases the ultimate load carrying capacity by one and a half times irrespective of the eccentricity of loading.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.63-70
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• 2008

Strengthening method of steel-concrete composite bridges using external tendons has been found as one of the most effective techniques of reinforcement and its application is increasing. In this paper, experimental test was carried out to show the effects on the yield loading and ultimate loading of steel-concrete composite beams strengthened with various configurations of external tendons. Quantitative analysis is carried out to evaluate the effects of experimental variables such as tendon force, deviator, tendon eccentricity and the shape of strands.

• Proceedings of the KSRS Conference
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• v.1
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• pp.263-266
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• 2006

Now, on the developing COMS(Communication, Ocean and Meteorological Satellite) has solar panel on the South panel only. Therefore, the wheel off-loading has to be performed periodically to reduce a induced momentum energy by a asymmetric solar panel. One of two East/West station keeping maneuver to correct simultaneously longitude and eccentricity, orbit corrections may be performed during one of the two wheel off-loading manoeuvres per day to get enough observation time for meteorological and ocean sensor. In this paper, we applied a linearized orbit maneuver equation to acquire maneuver time and delta-V. Nonlinear simulation for the station keeping is performed and compared with general station keeping strategy for fuel reduction.

• Journal of Korean Society of Steel Construction
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• v.13 no.1
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• pp.81-89
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• 2001

Experiments and the parametric based on finite element model were conducted to investigate the behavior and strength of a gussettube connection concerned with eccentricity and selenderness ratio. Because of limitations in loading capacity the specimens were fabricated with 1/3 scale of full size. Of primary interest here are the ultimate strength of connections having eccentricity caused by lateral loads. As a result the effect of eccentricity on the buckling strength was examined and the validity of the finite element model adopted in this study was verified through comparing with test results.

• Steel and Composite Structures
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• v.45 no.1
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• pp.23-38
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• 2022

This paper presents experimental and analytical studies of eccentrically loaded concrete-filled double steel (CFDST) and concrete-filled double skin tube (DCFST) columns having outer stainless steel tube. Eighteen CFDST and DCFST column specimens were manufactured and tested to examine the strength and load-deflection responses. In the study, the main parameters were concrete strength, load eccentricity, cross section and slenderness. The strengths, load-deflection diagrams and failure patterns of the columns were observed. In addition, the tested CFDST and DCFST columns were analyzed to attain the capacity and load versus lateral deflection responses. The obtained theoretical results were compared with the test results. A parametric study was also performed to research the effects of the ratio of eccentricity (e/H_o) slenderness ratio (L/r), H_o/t_o ratio, H_i/t_i ratio and the concrete compressive strength on the behavior of columns. In this work, the obtained results indicated that the ductility and capacity of columns were affected by cross section, concrete strength, steel strength, loading eccentricity and slenderness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1238-1244
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• 1999

Using a cylindrical worm gear under the actual condition of static loading, tooth fillet strains and transmission errors have been measured. The maximum strain occurs on the filet region of the center of the 1st mating tooth. Tooth fillet strain changes most sensitively according to the variations of the center distance and recess side eccentricity than the access side eccentricity. Even the no-backlash worm gear shows the transmission errors.