• Coupled systems mechanics
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• v.8 no.1
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• pp.19-38
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• 2019

The influence of torsional rigidity of hinged flexible appendage on the linear dynamics of flexible spacecrafts with liquid on board was analyzed by considering the spacecraft's main body as a rigid tank, its flexible appendages as two elastically supported elastic beams, and the onboard liquid as an ideal liquid. The meniscus of the liquid free surface due to surface tension was considered. Using the Lagrangian of the spacecraft's main body (rigid tank), onboard liquid, and two beams (flexible appendages) in addition to assuming the system moved symmetrically, the coupled system frequency equations were obtained by applying the Rayleigh-Ritz method. The influence of the torsional rigidity of the flexible appendages on the spacecraft's coupled vibration characteristics was primary focus of investigation. It was found that coupled vibration modes especially that of appendage considerably changed with torsion spring parameter ${\kappa}_t$ of the flexible appendage. In addition, variation of the main body displacement with system parameters was investigated.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.24-32
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• 2002

A program is developed to analyze and design the frequency and rigidity of the corrugated plates with various corrugation shapes (the considered corrugation shapes are triangular and trapezoidal) and 36 kinds of boundary conditions using smeared theory. The system is consisted of input, solution and output routines, and its routine is made up pull-down menu type and run in Window basis using Visual Basic Language. The input routine helps the design engineers to make the input data user-friendly. The solution routine uses the homemade solver. In the output routine, automatic designs can be done using AutoCAD and Intent Tool package by interfacing the input data.

• Coupled systems mechanics
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• v.9 no.2
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• pp.147-161
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• 2020

Constructive merging of "basic" systems of different behavior creates hybrid systems. In doing so, the structural elements are grouped according to the behavior in carrying the load into a geometric order that provides sufficient load and structure functionality and optimization of the material consumption. Applicable in all materializations and logical geometric forms is a transparent system suitable for the optimization of load-bearing structures. Research by individual authors gave insight into suitable system constellations from the aspect of load capacity and the approximatemethod of estimating the participation of partialstiffnesswithin the rigidity ofthe hybrid system. The obtained terms will continue to be the basisfor our own research of the influence of variable parameters on the behavior of hybrid systemsformed of glued laminated girder and cable of different geometric shapes. Previous research has shown that by applying the strut-type hybrid systems can increase the load capacity and reduce the deformability ofthe free girder.The implemented parametric analysis pointsto the basic parameterin the behavior of these systems-the rigidity ofindividual elements and the overallstiffnessofthe system.The basic idea ofpre-stressing is that, in the load system or individual load-bearing element, prior to application of the exploitation load, artificially challenge the forcesthatshould optimize the finalsystembehaviorin the overall load. Pre-stressing is possible only if the supporting system orsystem's element possesssufficientstrength orstiffness, orreaction to the imposed forces of pre-stressing. In this paper will be presented own research of the relationship of partial stiffness of strut-type hybrid systemsofdifferentgeometric forms.Conducted parametric analysisofhybridsystemswithandwithoutpre-stressing, and on the example of the glulam-steel strut-type hybrid system under realistic conditions of change in the moisture content ofthe wooden girder,resulted in accurate expressions and diagramssuitable for application in practice.

• Fibers and Polymers
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• v.2 no.3
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• pp.148-152
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• 2001

Cotton yarns were coated with a polymer solution to hold surface fibers to the yam body, which caused fiber-fly generation during knitting process. The physical property of the coated yarn, especially a bending rigidity was investigated in order to evaluate the performance of the coated yam during knitting. SEM images showing the surface condition of the coated yarn demonstrated that the thickness of a coating material increased as the concentration of the coating solution increased. The results of the bending rigidity measured using KES-FB2 system showed that the bending rigidity of the coated yam increased as the concentration of the coating solution increased. The results also revealed the possibility that yarn coated with a low amount of coating material should be employed for further research of reducing fiber-fly generation during knitting process.

• KCI Concrete Journal
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• v.14 no.3
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• pp.111-120
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• 2002

This study proposes a joint model consisting of different types of members as a new structural system, and then investigates the resulting structural behavior. The joint model consists of a concrete-filled steel tube column (CFT) together with a steel reinforced concrete at the end plus reinforced concrete beam at the center. For comparison, two other joint models were designed, that are, a CPT with a reinforced concrete beam, and a CFT with a steel reinforced concrete at the end plus steel concrete beam at the center, then their joint capacity and rigidity, energy absorption capacity, etc., were all investigated. From the results, the CFT column with a steel reinforced concrete at the end plus steel concrete beam at the center was outstanding in terms of its capacity and rigidity. The results of this analysis demonstrate that an adequate connection type and reinforcement method with different materials of increasing the rigidity, thereby producing a capacity improvement along with protection from pre-fractures.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.195-198
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• 2002

Two types of conformal load-bearing antenna structure (CLAS) were designed with microwave composite laminates and Nomex honeycomb cores, to give both structural rigidity and good electrical performance. One is 4$\times$8 array for Synthetic Aperture Radar(SAR) system and the other is $5\times2$ array for wireless LAN system. Design was based on wide bandwidth, high polarization purity, low loss and good structural rigidity. We studied the design, fabrication and structural/electrical performances of the antenna structures. The flexural behavior was observed under a 3-point bending test, an impact test, and a buckling test. Electrical measurements were in good agreement with simulation results and these complex antenna structures have good flexural characteristics. The design of this antenna structure is extended to give a useful guide for sandwich panel manufacturers as well as antenna designers.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.786-793
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• 2006

For the purpose of developing a vibration-based tension force evaluation procedure for hangers in suspension bridges, a 3D finite element model of hangers is constructed in this paper. With the developed finite element formulation, a frequency-based sensitivity-updating algorithm is applied to identify the target cable system the proposed method is also able to identify the flexural rigidity. the axial rigidity, and the torsion rigidity of a cable. For a field application, a vibration test on hangers of the Yong Jong Grand Suspension Bridge is carried out and the collected data is used to verify the proposed method.

• Journal of Biomedical Engineering Research
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• v.31 no.4
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• pp.275-279
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• 2010

The purpose of this study was to quantify the clinical assessment of rigidity at wrist in patients with Parkinson's disease. The experimental system was designed that the effect of gravity was negated by restricting motion at the horizontal plane and inertia was predetermined from a biomechanical measurement. Forty five patients with Parkinson's disease participated in this study. Viscoelastic properties were calculated from the experimental data acquired during intermittent passive movement of wrist. Viscoelastic constants correlated well with the rigidity scores of UPDRS, i.e., Spearman's r=0.733 and 0.905 for spring and damping constants, respectively. The results suggest that viscoelastic properties can be used as quantitative measures of rigidity.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.115-121
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• 2000

This paper presents reducing method of profile error on a mechanical tuning for multi-spindle control of NC machine tools. To reduce the profile error in the feed drive system, it is useful to adopt same transfer function of multi spindle machine tools. By selecting the correction vector of servo rigidity and natural vibration on JK map, multi spindle control can be tuned by mechanical parameters with small profile error.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.2
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• pp.141-147
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• 2001

This paper presents a developing algorithm of checking errors of feed mechanism in the NC machine tool with DAC method. It is useful to check static and dynamic rigidity with relation between lost motion and current of rotor. For checking error of feed in assembly tuning with machining center proposed checking algorithm is useful.