• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.413-420
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• 2005

The purpose of this study was to determine differences of balance performance to upright standing, forward bending posture, and sudden load during forward bending posture in subjects with and without a history of low back pain. A study was conducted on 8 subjects with low back pain and 13 healthy subjects. Dynamic Balance System was used to measure the postural sway index, left-right sway index, and anterior-posterior sway index on balance performance. There were no differences between subject groups on balance performance during upright standing. Balance performance was increased in forward bending posture and decreased in sudden load during forward bending posture in subjects with low back pain. These results suggest that subjects with low back pain demonstrated increased activity and decreased reaction times of trunk muscles.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.728-736
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• 2017

In this study, the bending behavior of cross-laminated timber (CLT) connected by nails were investigated. Especially, the load-carrying capacity of the nail-jointed CLT under out-of-plane bending was predicted by the lateral resistance of the used nails. Three-layer nail-jointed CLT specimens and a nail connection were manufactured by 30 mm (thickness) ${\times}$ 100 mm (width) domestic species (Pinus koraiensis) laminas and Ø$3.15{\times}82mm$ nails using a nail-gun. Shear test for evaluating the nail lateral resistance and bending test for evaluating the load-carrying capacity of the nail-jointed CLT under out-of-plane bending were carried out. As a result, two lateral resistance of the used nail, the 5% fastener offset value and the maximum value, were 913 N and 1,534 N, respectively. The predicted load-carrying capacity of the nail-jointed CLT by the 5% offset nail lateral resistance was similar to the yield points on the actual load-displacement curve of the nail-jointed CLT specimens. Meanwhile, the nail-jointed CLT specimens were not failed until the tension failure of the bottom laminas occurred beyond the maximum lateral resistance of the nails. Thus, the measured maximum load carrying capacities of the nail-jointed CLT specimens, approximately 12,865 N, were higher than the predicted values, 7,986 N, by the maximum nail lateral resistance. This indicates that the predicted load-carrying capacity can be used for designing a structural unit such as floor, wall and roof able to support vertical loads in a viewpoint of predicting the actual capacities more safely.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.577-577
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• 1989

In this paper, a detail evaluation of ultimate strength of offshore unstiffened tubular members with bending and local denting damage which are subjected to combined axial force and bending moment and to component load is presented through theoretical and experimental approaches. Based upon the results obtained here, the damage effect on the ultimate strength of tubular member under combined loads and component load is investigated.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.77-86
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• 1989

In this paper, a detail evaluation of ultimate strength of offshore unstiffened tubular members with bending and local denting damage which are subjected to combined axial force and bending moment and to component load is presented through theoretical and experimental approaches. Based upon the results obtained here, the damage effect on the ultimate strength of tubular member under combined loads and component load is investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.1025-1030
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• 2007

Three kinds of metallic sandwich panels with quasi-Kagome truss cores have been analyzed on their mechanical behaviors subjected to bending load. According to the results of previous work on the optimal design, they were designed to have similarly high strength per weight with the identical overall sizes, i.e., the total length, the width, the core height. Differences were in the face sheet thickness and/or the thickness of the metal sheet from which the core was fabricated through expanding and bending processes. Under the bending load, they performed well as designed, as far as the maximum load is concerned. However, after the maximum load, the load-displacement curves were different each other depending on the slenderness ratio of the truss elements composing the quasi-Kagome truss cores and the face sheet thickness. Namely, the slenderness ratio and the face sheet thickness governed stability of the elastic and plastic buckling. Therefore, if energy absorption characteristics or structural stability as well as the maximum load capacity are to be achieved, the sandwich panel with thick truss members and thick face sheet should be selected.

• Journal of the Korean Society of Safety
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• v.23 no.3
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• pp.17-24
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• 2008

Elbows with various shapes of local wall thinning were numerically analyzed by finite element method to get load-displacement curves and the maximum loads. Results were compared with the experimental data obtained by another study. Elastic-plastic analysis were carried out under the combined loading conditions of internal pressure and in-plane bending loads. Two types of bending loads were considered such as elbow opening mode and elbow closing mode. Also, two different wall thinning geometries were modeled. Wall thinning area located extrados or intrados of elbow inner surface was considered. Longitudinal and circumferential lengths of the thinning area and the thinned thickness were varied for analysis. The results showed that the maximum load of the wall-thinned elbow decreased with increasing of the circumferential thinning length and the thinned thickness in both of extrados and intrados thinning locations in both loading types. The maximum load obtained by the analysis were in good agreement with the experimentally measured maximum load with the same wall thinning type and dimensions. This supports accuracy of the analysis results obtained in this study.

• Steel and Composite Structures
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• v.25 no.3
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• pp.327-335
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• 2017

To gain more knowledge of aluminum foam sandwich structure and promote the engineering application, aluminum foam sandwich consisting of 7050 matrix aluminum foam core and 304 stainless steel face-sheets was studied under three-point bending by WDW-T100 electronic universal tensile testing machine in this work. Results showed that when aluminum foam core was reinforced by 304 steel face-sheets, its load carrying capacity improved dramatically. The maximum load of AFS in three-point bending increased with the foam core density or face-sheet thickness monotonically. And also when foam core was reinforced by 304 steel panels, the energy absorption ability of foam came into play effectively. There was a clear plastic platform in the load-displacement curve of AFS in three-point bending. No crack of 304 steel happened in the present tests. Two collapse modes appeared, mode A comprised plastic hinge formation at the mid-span of the sandwich beam, with shear yielding of the core. Mode B consisted of plastic hinge formation both at mid-span and at the outer supports.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.740-743
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• 2001

Sandwich structure is widely used in various fields of industry due to its excellent strength and stiffness compared with weight. We studied the sandwich structure which has honeycomb core type. We are concerned about its buckling and bending stress with respect to its side length, thickness and the height ratio of its unit core. After obtaining the buckling critical load of unit core, we applied it to the sandwich structure to observe the bending behavior. When we compared the buckling with bending stress under buckling critical load, we observed that models of which length ratio of unit honeycomb core, A, is lower than 0.04 and the thickness of core, t, is thicker than 0.09 mm, is subjected to the ultimate stress by bending before buckling.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.62-68
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• 2000

In order to automate straightening process of deflected beams an adaptive three-point bending controller is studies which estimates and controls springback of beams under three-point bending. An analytical load-deflection model for three-point bending of beams with circular cross sections is derived nondimensionally. In spite of variation of material and process parameters this model can be applied to springback estimation by measuring real-time values of reactive load and deflection of the beam. A hydraulic punch stroke controller is designed to take real-time controls of the permanent deflection of the beam. The validity of the proposed system is verified through experiments.

• Transactions of Materials Processing
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• v.10 no.1
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• pp.53-58
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• 2001

Set-up reference values, used in determining the optimum downcoiling tension, we experimentally verified in this study. During the actual downcoiling, the strip suffers both tension and bending force through the rotation of mandrel. Therefore, simulative test which can measure both tension and bending resistance of strip was performed to estimate set-up reference value for strip tension during downcoiling operations. The values obtained from the simulative test were correlated with the yield stress which has conventionally been used as reference values for downcoiling tension. The correlative analysis showed that the yield stress of strip can be a good reference value for downcoiling tension. Furthermore, the bending load also shows strong correlation with simulated values due to the close relationship between yield stress and bending load.