• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.409-412
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• 2003

ACI design code is not capable of evaluating the inter-effects between concrete and torsional reinforcement on the torsional resistance of the reinforced concrete beams. In this study, the failure strengths of the ten reinforced concrete beams subjected to pure torsion were evaluated using 3-dimensional strut-tie models. The analysis results obtained from the present study were compared with those obtained from the ACI design code. The comparison showed that the accuracy and performance of the present method were better than the ACI design code. Thus, the method implementing a 3-dimensional strut-tie model can be possibly applied to the analysis and design of the reinforced concrete beams subjected to pure torsion as a rational design method.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.373-376
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• 2004

The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The rectangular shaped corbel consist of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, rectangular shaped corbel is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. The results show that strut-tie model can be a rational and an economical design than current conventional design methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.31-39
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• 2014

In order to design rigid zone area of frame structures, it is important to predict the direction change of internal stresses according to the bending moment acting on the joint region. In this study, it was examined whether current highway bridge design standards are useful to design different types of rigid joints having a various haunch shapes. In addition, stress distributions of inside of various rigid joints were inspected using the linear elastic finite element analysis. Based on the results of finite element analysis, the strut-tie models to design rigid joints are proposed. Suggested by this study, the strut-tie models have a same level of accuracy to a linear elastic finite element analysis. The proposed strut-tie models will be useful to design reinforcement details of rigid joints having a various haunch types.

• Journal of the Korean Society of Costume
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• v.23
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• pp.169-181
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• 1994

The Purpose of this study is to help the neck-tie business enterprise establish the reasonable marketing strategy meeting consumer' needs by grasping their characteristic of purchasing neck-ties and their attitudes toward trademarks. The findings of this study are as follows : 1. It was shown that the neck-tie enterprise tended to appeal to megazines, catalogues , etc as promotional politics, while the tips obtained by consumers would come from the showcase at the purchasing place. and the consumer showed a positive response to the salesperson's advice. For this result, it is required to place further emphasis on the marketing policy such as the display of products at the store or the education of sales persons. 2. It was shown that the consumer tended to use the department store as the purchasing place remarkably, and so it could be found that the use of the department store is becoming generalized to the consumer. But is was shown that the consumer sensitive to prices tended to make use of the marketplace as the purchasing place, so the practical marketing strategy should be established in relation to this trend. 3. The important elements excreting an influence on the consumer's purchasing the neck-tie were shown to be in orders of design > color> harmony > with suit > price > quality, and the product differentiation policy used by the business enterprise to appeal to the consumer was shown to be in orders of design >color > quality > material > price. Accordingly , it was consistent with the consumer's criterion for choice to an extent. 4. It was shown that the selling price for the neck-tie brand actually was higher for imported or technically cooperated brands than for the home-made brand. Thus, the consumer's perception of the price for the neck-tie was consistent with in this regard, consumers did not feel some difference in quality between the home -made neck-tie brand and the imported or technically cooperated neck-tie brand . Therefore, it is important to produce the product capable of satisfying the consumer's need by manufacturing the own brand on basis of impored technology.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.596-601
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• 2008

This paper presents how to develop visual design tools for construction of strut-and-tie models(S (STM). STMs have shown internal force flows for dimensioning and proportioning of D-regions of reinforced concrete structures. In order to select an appropriate strut-and-tie model some interactive graphic tools are necessary to help designers compare alternatives by changing the geometry of initial STM. This study proposes to use force polygons representing the equilibrium state of STM. The change of STM dynamically shows change of force magnitudes by force polygon. Once the geometry of STM is determined the detailing design process is required in the next procedure.

• Computers and Concrete
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• v.19 no.5
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• pp.589-597
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• 2017

Strut-and-tie modeling method, which evolved on truss-model approach, has generally been preferred for the design of complex reinforced concrete structures and structural elements that have critical shear behavior. Some structural members having disturbed regions require exceptional detailing for all support and loading conditions, such as the beam-column connections, deep beams, short columns or corbels. Considering the general expectation of exhibiting brittle behavior, corbels are somewhat dissimilar to other shear critical structures. In this study, reinforcement layout of a corbel model was determined by the participation of structural optimization and strut-and-tie modeling methods, and an experimental comparison was performed against a conventionally designed model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1051-1057
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• 2000

A projected 100 kW APU gas turbine rotor-bearing system has a main outer shaft, which is composed of some numbers of segmented sections for manufacturing and assembly conveniences. For a secure assembly of the segmented sections a tie shaft or inner shaft is installed inside of the outer shaft and a tensional axial preload of 50,000 N is provided to it. In this paper it is intended to set-up a sound modeling method of the APU rotor system, and particularly, the influences of the tie shaft on the rotordynamic characteristics of the entire APU gas turbine rotor-bearing system are investigated. Analysis results show that as a conservative design practice the inner tie shaft should be actively modeled in the rotordynamic analysis of the APU rotor-bearing system, and its effects on the dynamic behaviors of the outer shaft should be thoroughly design-reviewed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.319-328
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• 2011

This paper introduces the construction of Strut-Tie model based on the Evolutionary Structural Optimization(ESO) method. Differently from conventional ESO method which uses plane stress elements, the introduced approach adopts the use of truss elements with the fact that the optimum topology of structures by ESO method is open a truss-like structure. Several examples are provided to demonstrate the capability of the proposed method in finding the best Strut-Tie models. In advance, it is shown that the introduced method is supported through the correlation studies between two-dimensional plane stress analysis and Strut-Tie models, and can be used effectively in practice, especially in shear design of complex reinforced concrete members where no previous experience is available.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1334-1340
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• 2017

In this paper, a tie-plate shape is optimized by using the numerical technique to reduce the stray load loss of the tie-plate which is a mechanical structure for assembling and supporting of the transformer core. The eddy current loss of the structure is calculated by an electromagnetic field FEM program and the results are compared with 4 different shapes of tie-plates. Since the thickness of the tie-plate is very thin, and the skin depth is very small, the number of FE elements for 3-D transformer model is too big to solve. So, the surface impedance boundary condition (SIBC) is used to reduce the system matrix size and its computing time. To verify the method a 2.5 MVA 22,900/380V distribution transformer is simulated using one objective function and three design variables with some constraints. The final optimized tie-plate has three slots of 6 mm width and 23 mm gap, and the loss is reduced by 75 %. Consequently, the proposed algorithm seems to be considerably applicable to electric machinery as well as power transformer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.437-446
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• 2014

In this study, the ultimate strengths of 13 slab-column joints and 51 torsional beams were evaluated to verify the validity of the strut-tie model approach presented in the companion paper. In addition, the design of the bridge pier subjected to multiple load combinations with longitudinal and lateral loads was conducted. The analysis results were compared with those by the provisions of BS 8110, ACI 318, and AASHTO-LRFD. The design results of the bridge pier were also compared with those by the provisions of ACI 318's sectional design method and AASHTO-LRFD's strut-tie model method.