• Explosives and Blasting
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• v.30 no.2
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• pp.43-51
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• 2012

The Demolition blasting has been applied for buildings and structures so far. In this study, however, a confined vessel blasting filled with water has been focused. A small amount of explosives were placed in a sealed vessel with water, perfect elastic body, supposed as a relay agent in it, and the blasting aspect was observed. Blasting pressure was standardized by Abel's equation of state. In result, if there was a relay agent in it, the pressure vessel was torn apart with smaller power than its tensile strength. If there was not, it needed 7.1~8.5 times as much power as the previous one, and the blasting pressure had not also affected the demolition and it had gone or vanished until it reached a certain point, In terms of pressure vessel made by steel, the elastic-plastic failure was took a place, and the first yield point happened along the welded area as a form of heating plastic failure we thought.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.14-17
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• 1999

The wrinkling behavior of a thin sheet with perfect geometry is a kind of compressive instability. The compressive instability is influenced by many factors such as stress state mechanical properties of the sheet material geometry of the body contact conditions and plastic anisotropy. The analysis of compressive instability in plastically deforming body is difficult considering all the factors because the effects of the factors are very complex and the instability behavior may show wide variation for small deviation of the factors. In this study the bifurcation theory is introduced for the finite element analysis of puckering initiation and growth of a thin sheet with perfect geometry. All the above mentioned analysis and the post-bifurcation behavior is analyzed by introducing the branching scheme proposed by Riks. The finite element formulation is based on the incremental deformation theory and elastic-plastic material modeling. in order to investigate the effect of plastic anisotropy on the compressive instability a square plate that is subjected to compression in one direction and tension in the other direction is analyzed by the above-mentionedfinite element analysis. The critical stress ratios above which the buckling does not take place are found for various plastic anisotropic modeling method and discussed. Finally the effect of plastic anisotropy on the puckering behavior in the spherical cup deep drawing process is investigated.

• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.202-206
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• 2013

A submerged floating railway is an innovative tunnel infrastructure passing through the deep sea independent of wave and wind so that high speed trains can run on it. It doesn't depend on water depth and is cost effective due to modular construction on land. The construction period can be reduced drastically. This paper introduces the concept design of a submerged floating railway, and for securing safety, proposes a method to analyze the structural behavior of the body in case of collision with a submarine. The theory of a beam with an elastic foundation was used to calculate the equivalent mass of the body so that the perfect elastic collision could be applied to calculate the collision velocity. The maximum deformation and bending moment was analyzed based on energy conservation. To verify the results, a collision analysis using a finite element analysis code was made. Comparing the results confirmed that this simplified collision analysis method gives enough accurate deformation and bending moment to be used for actual estimation in the initial design stage.

• Computers and Concrete
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• v.21 no.2
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• pp.219-229
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• 2018

In this paper, a modified rigid body spring model (RBSM) is proposed and used to analyze the damage and failure process of reinforced concrete (RC) structures. In the proposed model, the concrete is represented by an assembly of rigid blocks connected with a uniform distribution of normal and tangential springs to simulate the macroscopic mechanical behavior of concrete. Steel bars are evenly dispersed into rigid blocks as a kind of homogeneous axial material, and an additional uniform distribution of axial and dowel springs is defined to consider the axial stiffness and dowel action of steel bars. Perfect bond between the concrete and steel bars is assumed, and tension stiffening effect of steel bars is modeled by adjusting the constitutive relationship for the tensile reinforcement. Adjacent blocks are allowed to separate at the contact interface, which makes it convenient and easy to simulate the cracking process of concrete. The failure of the springs is determined by the Mohr-Coulomb type criterion with the tension and compression caps. The effectiveness of the proposed method is confirmed by elastic analyses of a cantilever beam under different loading conditions and failure analyses of a RC beam under two-point loading.

• Journal of the Korean Society of Costume
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• v.53 no.3
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• pp.137-154
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• 2003

The purpose of this study is firstly to survey the social and cultural background of 20th century and women's status, and to identify what the ideal body is like and what the elements of outer garment and underwear are and the techniques to incarnate the ideal beauty. Various papers are referenced for theoretical study and the elements and techniques of underwear are analyzed based on photographical materials. This paper concludes as follows. In 1910's, ideal beauty has changed to H-style. In other words, the outer garment has confined the lower part of the body with plain H-type Hobble silhouette to express plump bust, somewhat slim waist, and small hips, As the underwears, cylindrical corsets which fasten from under the bust down to lap, brassiere which are helpful for plump bust, and artificial busts were worn. In 1920's, outer garment were Straight box silhouette style which were cut as tubular without dart, and the underwears were corselets which have been tubular from the bust to hip and the tubular chemi-knickers. The former corsets which had been hard-boned and been fastened with strings have been replaced by the hook closure due to the development of elastic joining method. In 1930's, women pursued perfect body showing the line of bust, waist, and hip. In order to express elegant beauty of female of Slim and long silhouette, Doter and underwear have been cut with bias and gore, and soft and flexible materials were flowed along the body. World war II in 1940's has made the women as social. Ideal beauty has changed to Short straight box silhouette which no more shows body line. Outer and underwears were simple and Practical style. In 1950's, ideal beauty was well-matured, elegant Women which were represented by round shoulder, conical breast, tiny waist and round hip. Outer garment showed Hourglass silhouette representing the body-tight suits with round shoulder pad and the wide flare skirts. As the underwears, conical brassiere by top circular stitch were preferred for plump and bulged bust and tight corsets for tiny waist and magnificent petticoats were worn.