• Title/Summary/Keyword: ideal strength

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Study of Effective Stiffness and Effective Strength for a Pinwheel Model combined with Diamond Truss-Wall Corrugation (P-TDC) (다이아몬드 트러스 벽면으로 구성된 P-TDC 모델의 강성 및 강도 연구)

  • Choi, Jeong-Ho
    • Journal of the Korean Society of Industry Convergence
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    • v.19 no.3
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    • pp.109-124
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    • 2016
  • The objective of this paper is to find the density, stiffness, and strength of truss-wall diamond corrugation model combined with pinwheel truss inside space. The truss-wall diamond corrugation (TDC) model is defined as a unit cell coming from solid-wall diamond corrugation (SDC) model. Pinwheel truss-wall diamond corrugation (P-TDC) model is made by TDC connected with pinwheel structure inside of the space. Derived ideal solutions of P-TDC is based on truss-wall and pinwheel truss model at first. And then it is compared with Gibson-Ashby's ideal solution. To validate the ideal solutions of the P-TDC, ABAQUS software is used to predict the density, strength, and stiffness, and then each of them are compared to the ideal solution of Gibson-Ashby with a log-log scale. Applied material property is stainless steel 304 because of having cost effectiveness. Applied parameters for P-TDC are 1 thru 5 mm diameter within fixed opening width as 4mm. In conclusion, the relative Young's modulus and relative yield strength of the P-TDC unit model is reasonable matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, P-TDC model is hoped to be applied to make sandwich core structure by advanced technologies such as 3D printing skills.

Development of Effective Stiffness and Effective Strength for a Truss-Wall Rectangular model combined with Micro-Lattice Truss (트러스 벽면과 미세격자 트러스로 구성된 정육면체 단위모델의 강성 및 강도 개발)

  • Choi, Jeong-Ho
    • Journal of the Korean Society of Industry Convergence
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    • v.19 no.3
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    • pp.133-143
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    • 2016
  • The objective in here is to find the density, stiffness, and strength of truss-wall rectangular (TWR) model which is combined with lattice truss (MLT) inside space. The TWR unit-cell model is defined as a unit cell originated from a solid-wall rectangular (SWR) model and it has an empty space inside. Thus, the empty space inside of the TWR is filled with lattice truss model defined as TWR-MLT. The ideal solutions derived of TWR-MLT are based on TWR with MLT model and it has developed by Gibson-Ashby's theory. To validate the ideal solutions of the TWR-MLT, ABAQUS software is applied to predict the density, strength, and stiffness, and then each of them are compared with the Gibson-Ashby's ideal solution as a log-log scale. Applied material property is stainless steel 304 because of cost effectiveness and easy to get around. For the analysis, SWR and TWR-MLT models are 1mm, 2mm, and 3mm truss diameter separately within a fixed 20mm opening width. In conclusion, the relative Young's modulus and relative yield strength of the TWR-MLT unit model is reasonably matched to the ideal expectations of the Gibson-Ashby's theory. In nearby future, TWR-MLT model can be verified by advanced technologies such as 3D printing skills.t.

Application of Fuller's ideal curve and error function to making high performance concrete using rice husk ash

  • Hwang, Chao-Lung;Bui, Le Anh-Tuan;Chen, Chun-Tsun
    • Computers and Concrete
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    • v.10 no.6
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    • pp.631-647
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    • 2012
  • This paper focuses on the application of Fuller's ideal gradation curve to theoretically design blended ratio of all solid materials of high performance concrete (HPC), with the aid of error function, and then to study the effect of rice husk ash (RHA) on the performance of HPC. The residual RHA, generated when burning rice husk pellets at temperatures varying from 600 to $800^{\circ}C$, was collected at steam boilers in Vietnam. The properties of fresh and hardened concrete are reviewed. It is possible to obtain the RHA concrete with comparable or better properties than those of the specimen without RHA with lower cement consumption. High flowing concrete designed by the proposed method was obtained without bleeding or segregation. The application of the proposed method for HPC can save over 50% of the consumption of cement and limit the use of water. Its strength efficiency of cement in HPC is 1.4-1.9 times higher than that of the traditional method. Local standards of durability were satisfied at the age of 91 days both by concrete resistivity and ultrasonic pulse velocity.

A Qualitative Study on Acceptance of Korean Wave Culture and Internalization of Ideal Beauty among Vietnamese Female Students in Korea (베트남 여성 유학생의 한류 문화 수용과 이상적 미 내면화 경험에 대한 질적 연구)

  • Kang, Yeonghoon;Lee, Ha Kyung;Kim, Woo Bin
    • Fashion & Textile Research Journal
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    • v.22 no.4
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    • pp.456-468
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    • 2020
  • Vietnam is becoming a leading country in the consumption of Korean wave. Many Vietnamese students have visited Korea due to a significant interest in the Korean wave. This study used focus group interviews with 12 Vietnamese female students in order to examine the experience of the Korean wave acceptance (RQ1), the experience of internalization toward ideal beauty (RQ2) and differences of internalization towards ideal beauty depending on the living period in Korea (RQ3). First, the results of RQ1 showed that Vietnamese students were accepting the Korean wave through media, Korean and social interaction in their daily lives. They also have a positive attitude toward Korean cosmetics and K-pop among various content of the Korean wave. Second, four focal meanings were composed through RQ2. They were the standards of ideal beauty, the causes of ideal beauty internalization and the results of ideal beauty internalization. The results of ideal beauty internalization were separated into the perception dimension and behavior dimension. Last, the results of RQ3 found that the strength of internalization of ideal beauty can very depending on the living period in Korea. This study has academic implications in that it understands Vietnamese female students who become a member of Korean society from a sociocultural perspective. The results of this study are useful to establish practical implications for young Vietnamese consumers to build desirable aesthetic values.

Aluminium Titanate Sintering Study Aimed at Rational Design of Microstructure for Optimal Thermal Shock Characteristics

  • Alecu, Ioan D.;Stead, Rodney J.
    • The Korean Journal of Ceramics
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    • v.5 no.1
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    • pp.78-81
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    • 1999
  • Aluminium titanate is highly anisotropic in thermal expansion. As a result, thermal stresses build up in the material and intergranular cracks can develop. Both the outstanding thermal shock resistance and the low mechanical strength of aluminium titanate ceramics are a result of intergranular microcracking. The authors have previously identified a possibility of remarkably increasing fracture toughness of aluminium titanate without excessive penalty on strength. The paper shows that sintered density and porosity measurements can be used for optimizing the sintering and microstructure of aluminium titanate for an ideal balance between toughness and strength and, hence, the best thermal shock resistance.

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An approach of using ideal gradating curve and coating paste thickness to design concrete performance-(2) Experimental work

  • Wang, H.Y.;Hwang, C.L.;Yeh, S.T.
    • Computers and Concrete
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    • v.10 no.1
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    • pp.35-47
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    • 2012
  • The ideal gradating curve is used in this study to estimate densified aggregate blended ratio and total surface area of aggregate, there by under assigned paste amount of concrete, and coating paste thickness can then be deduced. Four groups of concrete mixtures were prepared and the corresponding concrete properties, such as workability, compression strength, ultrasonic velocity, surface resistivity and chloride ion penetration, were measured and finally the results are interpreted in terms of "coating thickness". The result shows as the coating thickness of the concrete is higher than critical one, the coating thickness on aggregate does affect the workability, and whatever workability is required the superplasticizer can be adjusted to achieve the demand workability. Under a fixed paste quality at the same age, coating paste thickness is inversely proportional to the concrete properties, especially as the coating thickness gets thinner.

A reliable approach for determining concrete strength in structures by using cores

  • Durmus, Aysegul;Ozturk, Hasan Tahsin;Durmus, Ahmet
    • Computers and Concrete
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    • v.11 no.5
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    • pp.463-473
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    • 2013
  • As known, concrete classes are described as strength of standard specimens produced and kept in ideal conditions, not including reinforcement and not subjected to any load effect before. Under the circumstances, transforming core strengths to the standard specimen strength is necessary and considering all parameters, affected on the core strength, is inevitable. In fact, effects of the reinforcement and the load history on concrete strength are generally neglected when these mentioned transforms are performing. The main purpose of this paper is investigating the effects of the reinforcement and the load history on the core strength. This investigation is experimentally performed on cores drilled from specimens having different keeping conditions, reinforced, unreinforced, subjected to bending and central pressure in various proportions of failure load during specified periods. Obtained results show that the importance of these effects cannot be neglected.

A Change of fashin IIIustration by the Ideal Type of Human Body Beauty (인체미의 이상형에 따른 패션 일러스트레이션의 변화)

  • 전경숙
    • Journal of the Korean Society of Costume
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    • v.28
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    • pp.65-84
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    • 1996
  • The purpose of this study is to analyze the relation between the beauty of human body and the fashion illustration in each period And I attained my object through the investigation of features and changes of illustration which is given a vivid description of the features and development of ideal humam body beauty. By various methods I studied this subject. Frist I refered to sundry records Secondly I investiated the fashion illustrations which are included in Vogue. On the basis of this data I grasped the ideal types of human body beauty which is founded during the social change in each 10 years. And I analyzed the relation be-tween the ideal type and fashion illustration which show the change of fashion. The summary of result is as follows. 1. In the early part of the 20th century the beauty of human body is represented with the figure of large-sized beauty which emphasize shoulder and bust. And fashion ikllustration show 9 life-size broad shoulder full bust lim waist and hourglass silhouette. 2, In the 1910s the swell of strength vanishes gradually and shoulder and sleeve are straight type. And fashion illustration show 7 life-size high waist line. And that is tublar sil-houette of high waist and streamline shape in which bust and hip are not emphasized. 3. In the 1920s the ideal type of human body beauty is straight type which shows flat bust and unexaggerate hip. And fashion illus-tration is about 8 life-size tublar silhouette of low waist and lunger and slimmer and young style in which bust and hip are not emph-asized. 4. In the 1930s the ideal is womamly slim and long style. Fashion illustration is about 8 life-size and slim & long silhouette in which waist line is emphasized and bust and hip line come out. 5. In the 1940s the ideal type is womamly style which has narrow shoulder rich bast and slim waist. And fashion illustration is about 7 life-size and hourglass silhouette which has unartificial shoulder slim waist and empha-sized bust. 6. In the 1950s the ideal type is that of ro-bust health which emphasize build and muscu-lar system. And fashion illustration is 8.5 life-size and show full bust and made waist slimmer. That is sheath silhouette. 7. In the child who has full face with large eyeball slender and long leg: narrow and immatured body comparatively big head. And fashion illus-tration is 7 life-size and show slim and long neck flat bust long and slim limbs and big head. That is H type silhouette. 8. In the 1970s the ideal type is high stat-ure flat breast small hip and wide shoulders. And fashion illustration is wide shoulders and slim waist as 11 life-size and straight sil-houete. 9. In the 1980s the ideal type is extremely emphasized breadth of shoulder because healthy body and muscle are recognized as the symbol of ideal attractiveness. And fashion il-lustration is about 8.5 life-size and show mus-cular slim type that is slim silhouette. 10 At the present time the ideal type is slim and tall type which is empasized healthy beauty. And fashion illustration is 12 life-size which has healthy body and skin So that is slim and long type.

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Dog bone shaped specimen testing method to evaluate tensile strength of rock materials

  • Komurlu, Eren;Kesimal, Ayhan;Demir, Aysegul Durmus
    • Geomechanics and Engineering
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    • v.12 no.6
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    • pp.883-898
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    • 2017
  • To eliminate the holding and gluing problems making the direct tensile strength test hard to be applied, a new method of testing specimens prepared using lathe machine to make the dog bone shape is assessed whether it could be applied to determine accurate direct tensile strength values of rock materials. A series of numerical modelling analyses was performed using finite element method to investigate the effect of different specimen and steel holder geometries. In addition to numerical modelling study, a series of direct tensile strength tests was performed on three different groups of rock materials and a rock-like cemented material to compare the results with those obtained from the finite element analyses. A proper physical property of the lathed specimens was suggested and ideal failure of the dog bone shaped specimens was determined according to the results obtained from this study.

Towards improved models of shear strength degradation in reinforced concrete members

  • Aschheim, Mark
    • Structural Engineering and Mechanics
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    • v.9 no.6
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    • pp.601-613
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    • 2000
  • Existing models for the shear strength degradation of reinforced concrete members present varied conceptual approaches to interpreting test data. The relative superiority of one approach over the others is difficult to determine, particularly given the sparseness of ideal test data. Nevertheless, existing models are compared using a suite of test data that were used for the development of one such model, and significant differences emerge. Rather than relying purely on column test data, the body of knowledge concerning degradation of concrete as a material is considered. Confined concrete relations are examined to infer details of the degradation process, and to establish a framework for developing phenomenologically-based models for shear strength degradation in reinforced concrete members. The possibility of linking column shear strength degradation with material degradation phenomena is explored with a simple model. The model is applied to the results of 7 column tests, and it is found that such a link is sustainable. It is expected that models founded on material degradation phenomena will be more reliable and more broadly applicable than the current generation of empirical shear strength degradation models.