• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.395-411
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• 1993

The purpose of this study was to examine the clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, the cavities were prepared on maxillary first premolar and filled with gold inaly. A two - dimensional model was composed of 1037 - node triangle elements. In this model, isthmus was varied in width at 1/4, 1/3 and 1/2 of intercuspal width and material properties were given for four element groups, i.e., enamel, dentin, pulp and gold. The 500N occlusal load varied in direction and it was examined using three types of load : concentrated load, divided load and distributed load. The models were also examined with empty cavities using the devided load and distributed load. These models were analyzed the displacement and strees distribution by the two - dimensional Finite Element Method. The results were as follows : 1. All experimental models which filled with gold inlay after cavity preparation were similar direction of displacement with control model under same load type. But in the models with empty cavities, as isthmus width was wider, the degree of displacement was increased at same load type. 2. Among the experimental models which were filled with gold inaly after cavity preparation, the model II showed the least stress concentration under concentrated load and divided load. But in the models with empty cavities, the model III showed the largest stress concentration and tooth fracture is expected regardless isthmus width. 3. All experimental models showed similar displacement pattern beneath restorative material under a concentrated load. In the models with empty cavities, a divided load resulted in a lingual displacement of the lingual cusp, but a distributed load resulted in a buccal displacement of the lingual cusp. In regard to the above results, the restored models were stronger than empty models in respect to the bending moment and tensile stress. The empty models are expected to fracture regardless isthmus width. The safest isthmus width was 1/3 of intercuspal distance, which showed the least stress concentration in respect to the effect of stress distribution.

• Structural Engineering and Mechanics
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• v.37 no.1
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• pp.61-77
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• 2011

Static and dynamic responses of a completely free elastic beam resting on a two-parameter tensionless Pasternak foundation are investigated by assuming that the beam is symmetrically subjected to a uniformly distributed load and concentrated load at its middle. Governing equations of the problem are obtained and solved by paying attention on the boundary conditions of the problem including the concentrated edge foundation reaction in the case of complete contact and lift-off condition of the beam ina two-parameter foundation. The nonlinear governing equation of the problem is evaluated numerically by adopting an iterative procedure. Numerical results are presented in figures to demonstrate the non-linear behavior of the beam-foundation system for various values of the parameters of the problem comparatively by considering the static and dynamic loading cases.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.5
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• pp.51-64
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• 1991

In this paper, an attempt is made to analyze the impulsive stress directly underneath the concentrated impact point for a supported square plate by using the three-dimensional dynamic theory of elasticity and the potential theory of displacement (stress function) on the supposition that the load, F$_{*}$0 sin .omega.t, acted on the central part of it. The results obtained from this study are as follows: 1. The impulsive stress cannot be analyzed directly underneath the acting point of concenrated impact load in privious theories, but can be analyzed by using the three-dimensional dynamic theory of elasticity and the potential theory of displacement. 2. Theorically, with increasing the pulse width of applied load, it was possible to clarify that the amount of stress in the point of concentrated impact load was increased and that of stress per unit impulse was decreased. 3. The numerical inversion of laplace transformation by the use of the F.F.T algorithm contributes the reduction of C.P.U time and the improvement of the accuracy or results. 4. In this paper recommended, it is found that the approximate equation of impact load function P (.tau.) = A.tau. exp (-B.tau.), and P (.tau.) =0.85A exp (-B.tau.) sinC.tau. could actually apply to all impact problem. In compared with the experimental results, the propriety of the analytical method is reasonable.

• Steel and Composite Structures
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• v.41 no.5
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• pp.637-648
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• 2021

Nowadays, one of the practical, fast and easy ways to strengthen steel elements is the use of Carbon Fiber Reinforced Polymer (CFRP). Most previous research in the CFRP strengthening of steel members has carried out on straight steel members. The main difference between horizontal curved beams and straight beams under vertical load is the presence of torsional moment in the horizontal curved beams. In the other words, the horizontal curved beams are analyzed and designed for simultaneous internal forces included bending moment, torsional moment, and shear force. The horizontal curved steel beams are usually used in buildings, bridges, trusses, and others. This study explored the effect of the CFRP strengthening on the behavior of the horizontal curved square hollow section (SHS) steel beams. Four specimens were analyzed, one non-strengthened curved steel beam as a control column and three horizontal curved steel beams strengthened using CFRP sheets (under concentrated load and uniform distributed load). To analyze the horizontal curved steel beams, three dimensional (3D) modeling and nonlinear static analysis methods using ANSYS software were applied. The results indicated that application of CFRP sheets in some specific locations of the horizontal curved steel beams could increase the ultimate capacity of these beams, significantly. Also, the results indicated when the horizontal curved steel beams were under distributed load, the increase rate in the ultimate capacity was more than in the case when these beams were under concentrated load.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.130-143
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• 1995

The purpose of this study was to analyze the magnitude and distribution of stress using photoelastic model with the rigid connection using T-block attachment and non-rigid connection using key & keyway attachment. The vertical load of 16 Kg was applied on the central fossa of the tooth, the pontic and the implant, and the pattern and distribution under each condition was analyzed. The following results were obtained : 1. In case of vertical load on the central fossa of the implant, the stress was concentrated at the apex of the implant involving the mesial alveolar bone in both fixed partial denture with the rigid connection and that with the nonrigid connection and the stress concentration at the mesial cervical area of the implant was a little more in the nonrigid connection than in the rigid connection. 2. In case of vertical load on the central fossa of the pontic, the stress was concentrated at the apex of 2nd bicuspid in both 3 unit fixed partial denture with nonrigid connection and that with the rigid connection. The stress was more concentrated at the mesial alveolar bone of the implant, but the stress distribution at the natural teeth more favorable at the rigid connection than at the non-rigid connection in case of 4 unit fixed partial denture. 3. In case of vertical load of the central fossa of the 2nd bicuspid, much stress with 3 fringe order was observed at the apex of the 2nd bicuspid in the 3 unit fixed partial denture, but relatively even stress distribution was observed at the apex of the implant, the 1st and 2nd bicuspid, and the adjacent cuspid in the 4 unit fixed partial denture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4642-4647
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• 2011

Solution for elastic foundation of plane strain state was derived by the application of variational method. Functions of the transverse distribution of the displacements for the analysis were chosen as linear functions. Loading conditions considered for the analysis were concentrated load and distributed load. Under the loading condition of the concentrated load, surface displacement was decreased drastically as the distance from the point of the loading increased. Under the loading condition of the distributed load, surface displacements were more uniformly distributed beneath the loading area when the ratio of the half of the loading width to the depth(B/H) of the compressible layer was greater. The surface displacement was more quickly converged from the edge of the loading area as the ratio(B/H) increased.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.409-417
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• 2012

SWAT model was applied for the Nakdong River Basin to characterize water quality variability and assess the feasibility of using the load duration curve to water quality management. The basin was divided into 67 sub-basins considering various watershed environment, and rainfall runoff and pollutant loading were simulated based on 6 year measurements of meteo-hydrological data, discharge data of treatment plants, and water quality data (SS, T-N and T-P). The results demonstrate that non-point source loads during wet season increase by 80 ~ 95% of total loads. Although the rate of water flow governs the amount of SS that is transported to the main streams, nutrient concentrations are highly elevated during dry season by being concentrated. This phenomenon is more pronounced in the lower basin, receiving large amounts of urban point source discharges such as treated sewages. Also, the load duration curves (LDC) demonstrate dominant source problems based on the load exceedances, showing that SS concentrations are associated with the rainy season and nutrients, such as T-P, may be more concentrated at low flow and more diluted at higher flow. Overall, the LDC method could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• Journal of Ocean Engineering and Technology
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• v.19 no.5 s.66
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• pp.34-42
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• 2005

The cable connection zone of the cable-stayed bridge transfers deal-load, live-load, and second-load to the cables on the structural joint zone of the cables and the main girders are the most critical parts in which big cable tensile forces are generated by those loads. Therefore, it is necessary to thoroughly check the main girder, structurally to secure the required stability. Because of the heavy tensile force of cables linked in the connection zone of the cable-stayed bridge, locally concentrated stress, as well as the dispersion of stress, occurs in the structurally contacted point of cable and main girder thus, we need to make a thorough investigation through a detailed structural analysis. Directly delivering the tensile force to the connection zone of the cable, the consequently big effect in the tensile force fluctuation caused by the live-load will make it necessary to review the fatigue strength. As the connection zone of the cable is designed to resist the tensile force of the cable, which is applied to a connecting section as a concentrated force, thick plates are used. These plates are frequently made of welded structure, thus, the investigation of the welding workability is inevitable.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1051-1052
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• 2011

This paper deals with optimum design criteria to minimize the torque ripple of a concentrated winding Synchronous Reluctance Motor(SynRM) using Response Surface Methodology(RSM). The feasibility of using RSM with the finite element method(FEM) in practical engineering problem is investigated with omputational examples and comparison between the fitted response and the results obtained from an analytical solution according to the design variables of stator and rotor in concentrated winding SynRM(6slot). The focus of this paper is the efficiency evaluation on the basis of load condition in a Concentrated Winding Synchronous Reluctance Motor and distributed Winding Synchronous Reluctance Motor.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1296-1305
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• 2009

This paper has the object of investigating dynamic stability of stiffened tapered thick plate with concentrated mass on Pasternak foundation by means of finite element method and providing kinematic design data for mat of building structures. Finite element analysis of stiffened tapered thick plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with 10, 100, 1000 and the shear foundation parameter is 5, 10, concentrated mass is $0.25m_c$, $1.0m_c$, tapered ratio is 0.25, 0.5. The ratio of In-plane force to critical load is applied as $0.4\sigma_{cr},\;0.6\sigma_{cr},\;0.8\sigma_{cr}$ respectively. This paper analyzed varying tapered ratio.