• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.117-118
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• 2006

The objective of this paper is to investigate into bending and failure characteristics of ISB panel with dimple shapes as inner structures. Through three-points bending test, the force-displacement curve and the failure shape are obtained to examine the deformation pattern, characteristic data including maximum load and displacement at the maximum load and failure pattern for the ISB panel. In addition, the influence of design parameters for ISB panel on the bending stiffness and failure mode has been found. From the results of the experiments, it has been shown that bending and failure characteristics of the ISB panel can be controlled by the ratio of radius and the direction of the material.

• Structural Engineering and Mechanics
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• v.38 no.3
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• pp.261-281
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• 2011

A new method of formulation of a class of elements that are immune to mesh distortion effects is proposed here. The simple three-noded bar element with an offset of the internal node from the element center is employed here to demonstrate the method and the principles on which it is founded upon. Using the function space approach, the modified formulation is shown here to be superior to the conventional isoparametric version of the element since it satisfies the completeness requirement as the metric formulation, and yet it is in agreement with the best-fit paradigm in both the metric and the parametric domains. Furthermore, the element error is limited to only those that are permissible by the classical projection theorem of strains and stresses. Unlike its conventional counterpart, the modified element is thus not prone to any errors from mesh distortion. The element formulation is symmetric and thus satisfies the requirement of the conservative nature of problems associated with all self-adjoint differential operators. The present paper indicates that a proper mapping set for distortion immune elements constitutes geometric and displacement interpolations through parametric and metric shape functions respectively, with the metric components in the displacement/strain replaced by the equivalent geometric interpolation in parametric co-ordinates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.534-544
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• 2019

Because the pile-bent of IPM Bridge is projected from the soil surface, excessive displacement of abutment can be induced. According to design guide of IPM Bridge, the shape of the bridges used in this study was applied to the maximum applicable 120.0m span, 30-degree for skew angle, and 10.0m for the protruded pile-bent height. The maximum displacement by the maximum span application condition of the IPM Bridge was calculated using this bridge model, and the safety of a horizontal displacement of the IPM Bridge was investigated based on the allowable displacement presented by Bozozuk. The maximum horizontal displacement of the IPM Bridge was calculated to be larger in the winter shrinkage condition than in the summer expansion condition, the horizontal displacements were more affected by the length of a bridge than by the skew angle. And the vertical displacement was not affected by the skew angle and length. As the span increases, the horizontal displacement increases significantly, the horizontal displacement at 120.0m span length was found to exceed the allowable displacement proposed by Bozozuk. However, the moment generated in the pile-bent did not exceed the plastic moment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1370-1377
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• 2005

The bottom structure of an instrumented capsule is a part which is joined at the receptacle of the flow tube in the reactor in-core. A geometrical change of the bottom structure has an effect on the pressure drop and the vibration of the capsule. The out-pile test to evaluate the structural integrity of the material capsule called 04M-17U was performed by using a single channel and a half core test loop. From the pressure drop test, the optimized diameter of the cone shape's bottom structure which satisfies HANARO's flow requirement (19.6 kg/s) is 71 mm. The maximum displacement of the capsule measured at the half core test loop is lower than 1.0 mm. From the analysis results, it is found that the test hole will not be interfered with near the flow tubes because its displacement due to the cooling water is very small at 0.072 mm. The fundamental frequency of the capsule under water is 9.64 Hz. It is expected that the resonance between the capsule and the fluid flow due to the cooling water in HANARO's in-core will not occur. Also, the new bottom structure of a solid cone shape with 71 mm in diameter will be applicable to the material and special capsules in the future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.782-787
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• 2005

The bottom structure of an instrumented capsule is a part which is joined at the receptacle of the flow tube in the reactor in-core. A geometrical change or the bottom structure has an effect on the pressure drop and the vibration of the capsule. The out-pile test to evaluate the structural Integrity of the material capsule called 04M-l7U was performed by using a single channel and a half core test loop. From the pressure drop test, the optimized diameter of the cone shape's bottom structure which satisfies HANARO's flow requirement (19 6 kg/s) is 71 mm. The maximum displacement of the capsule measured at the half core test loop is lower than 1.0 mm. From the analysis results, it is found that the test hole will not be interfered with near the flow tubes because its displacement due to the cooling water is very small at 0.072 mm. The fundamental frequency of the capsule under water is 9.64 Hz. It is expected that the resonance between the capsule and the fluid flow due to the cooling water in HANARO's In-core will not occur. Also, the new bottom structure of a solid cone shape with 71 mm in diameter will be applicable to the material and special capsules in the future.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.139-149
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• 2011

A cable structures have the advantage that cover a large space without column but it is very sensitive to deal with shape control because of its flexibility. Especially, location of control member and needed elongation of member are important things. Therefore, the purpose of this paper is studied on displacement control technique for pre-stressed cable structures by force method considering order of control. The layout of this paper is as follows. Firstly, in section 2, the control technique by force method for cable structures is given. Secondly, section 3 briefly introduces simple cable net in order to apply control technique considering ordering of actuator. Finally, more complex example for effective member and the conclusion are in section 4 and 5, respectively.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.5
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• pp.553-560
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• 2015

Fracture mechanics analysis for cracked pipes is essential for applying the leak-before-break (LBB) concept to nuclear piping design. For LBB assessment, crack instability and leak rate should be predicted accurately for through-wall cracked pipes. In a nuclear piping system, elbows are connected with straight pipes by circumferential welding; this weld region is often considered a critical location. Hence, accurate crack assessment is necessary for cracks in the interface between elbows and straight pipes. In this study, the stress intensity factor (SIF) and elastic crack opening displacement (COD) were estimated through detailed 3D elastic finite element (FE) analyses. Based on the results, closed-form solutions of shape factors for calculating the SIFs and elastic CODs were proposed for circumferential through-wall cracks in the abovementioned interfaces under internal pressure. In addition, the effect of the elbow on shape factors was investigated by comparing the results with the existing solutions for a straight pipe.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.2
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• pp.98-106
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• 2019

Human-powered aircraft has wings with a shape of high aspect ratio which results in large bending displacement. This paper aims to improve the structural limitation by changing an incidence angle of the wings. The tendency change of bending displacement at the wing tip is observed assuming that airfoil and cross-sectional shape of the wing is fixed, and amount of the total lift generated is satisfied. Quasi-steady lift, drag and the aerodynamic moment are distributed with regard to sections of the wing. Those are analyzed using a numerical nonlinear lifting-line method and 'geometrically exact beam' (GEB) program in EDISON. 'Variational Asymptotic Beam Sectional Analysis' (VABS) program is used to check if the present wing is structurally solid. Furthermore, the predicted tip deflections are verified by comparing with DYMORE.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.574-580
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• 2022

While in the process of electroless plating of dendrite-shape copper with silver, various silver-coated copper (Ag@Cu) particles were prepared by using both displacement plating and reducing electroless plating. The physicochemical properties of Ag@Cu particles were analyzed by scanning electron microscope- energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Brunauer-Emmett-Teller analysis (BET), and it was confirmed that the silver coated by the reducing electroless plating was formed as nano-particles on the copper surface. Ag@Cu particles were compounded with an epoxy resin to prepare a conductive film, and its thermal stability was evaluated. We investigated the effect of the difference between the displacement plating and reducing electroless plating on the initial resistance and thermal stability of conductive films.

• Computers and Concrete
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• v.17 no.2
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• pp.227-240
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• 2016

An analytical study was conducted to investigate the effect of the shape and spacing of modified inclined studs used as shear connector between concrete and steel plate on the cyclic behavior of steel plate concrete (SC) shear wall. 9 different analysis cases were adopted to determine the optimized shape and spacing of stud. As the results, the skeleton curves were obtained from the load-displacement hysteresis curves, and the ultimate and yielding strengths were increased as the spacing of studs decrease. In addition, the strength of inclined studs is shown to be bigger compared to that of conventional studs. The damping ratios increased as the decrease of stiffness ratio. Finally, with decreasing the spacing distance of studs, the cumulative dissipated energy was increased and the seismic performance was improved.