Yielding Anisotropy of Rolling Textured High Purity α-Ti

Jong Woo Won(원종우),Yong-Hak Huh(허용학),Seong-Gu Hong(홍성구) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

The yield strength of rolling textured high purity -Ti was found to be significantly dependent on the loading direction, i.e., yielding anisotropy; normal direction (ND) > transverse direction (TD) > rolling direction (RD). Activation stresses for three important deformation modes (prismatic, basal, and pyramidal 〈a〉 slips) were calculated based on the Schmid factor (SF) and effective critical resolved shear stress. The calculation results revealed that the specific crystallographic orientation of the material, caused by rolling texture, influences the activity of each deformation mode by affecting the SF and this significantly varies with the loading direction, thereby inducing a change of a deformation mode dominating the material yielding. Prismatic 〈a〉 slip governed the yielding in the RD and TD, while basal 〈a〉 slip was responsible for the yielding in the ND.

A new cultivar of the Hardy Kiwifruit, Dae-Sung , with Large Fruit and High Productivity

Yong-seok Jang,Moon-Ho Lee,Byung-Sil Lee 한국육종학회 2007 한국육종학회지 Vol.39 No.3

Hardy Kiwifruit (A. arguta (Sieb. & Zucc.) Planch. ex Miq.) is one of the valuable species due to their edible fruits, high content of nutritious substances, especially abundant of vitamin C, and distinctive flavor and medicinal usage. Therefore, we have developed a new cultivar of A. arguta with large fruits and high yielding. For this, 168 candidate plants were collected from wild populations in 12 locations from 4 provinces (Chungbuk, Gangwon, Gyeongnam, and Jeonbuk) from 1985 to 1987. A clone bank that contained highly productive, superior genotypes of A. arguta was assembled in 1988, and 32 excellent clones were selected in 1996 through the clone tests for growth and fruiting. From these clones, we have been regularly investigated yield trials for the fruiting characteristics to evaluation of major agronomic traits, which are the average of Fruit Length (FL), Fruit Width (FW), Weight of Fruit (WF) and Individual Yield (IY), during consecutive 6 years (1997~2002). Finally, we have selected the new A. arguta cultivar, “Dae-Sung” with large fruits and high yielding and registered as a new variety denomination and certificated for variety production and merchandising in 2006 (Table 1). This cultivar is characterized by a diploid plant and oblong type in the fruit shape, and is particularly characterized by large fruit size (Fig. 1, Table 3). The major agronomic traits of this cultivar showed the large selection effect with an average of 41.6 mm (FL), 29.9 mm (FW), 18.9 g (WF), and 25.9 kg (IY), which are 28.8%, -0.7%, 16.7%, and 232.0% compared to the mean of 29 sample trees, respectively (Table 2). Hardy Kiwifruit (A. arguta (Sieb. & Zucc.) Planch. ex Miq.) is one of the valuable species due to their edible fruits, high content of nutritious substances, especially abundant of vitamin C, and distinctive flavor and medicinal usage. Therefore, we have developed a new cultivar of A. arguta with large fruits and high yielding. For this, 168 candidate plants were collected from wild populations in 12 locations from 4 provinces (Chungbuk, Gangwon, Gyeongnam, and Jeonbuk) from 1985 to 1987. A clone bank that contained highly productive, superior genotypes of A. arguta was assembled in 1988, and 32 excellent clones were selected in 1996 through the clone tests for growth and fruiting. From these clones, we have been regularly investigated yield trials for the fruiting characteristics to evaluation of major agronomic traits, which are the average of Fruit Length (FL), Fruit Width (FW), Weight of Fruit (WF) and Individual Yield (IY), during consecutive 6 years (1997~2002). Finally, we have selected the new A. arguta cultivar, “Dae-Sung” with large fruits and high yielding and registered as a new variety denomination and certificated for variety production and merchandising in 2006 (Table 1). This cultivar is characterized by a diploid plant and oblong type in the fruit shape, and is particularly characterized by large fruit size (Fig. 1, Table 3). The major agronomic traits of this cultivar showed the large selection effect with an average of 41.6 mm (FL), 29.9 mm (FW), 18.9 g (WF), and 25.9 kg (IY), which are 28.8%, -0.7%, 16.7%, and 232.0% compared to the mean of 29 sample trees, respectively (Table 2).

Numerical and Experimental Study of Comb-Teeth Metallic Yielding Dampers

S. Garivani,A. A. Aghakouchak,S. Shahbeyk 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.1

In this paper, a new type of metallic yielding damper called comb-teeth damper, CTD, is introduced. CTD is made of steel plates and includes a number of teeth that dissipate energy through in-plane flexural yielding. An optimum geometry of teeth is suggested, which assures uniform distribution of stress along them and prevents strain localization. Finite element modeling is used to verify the design of proposed damper and to study nonlinear behavior of the damper subjected to monotonic as well as cyclic loading. Three full scale specimens have also been made and tested under cyclic loading. In order to restrict out-ofplane buckling of damper teeth, a special clamp has been designed. A numerical study has elaborated the effects of these clamps in comparison to increasing the thickness of individual tooth. The tested samples have tolerated considerable cumulative displacement in their hysteresis cycles without any significant loss of strength.

J-integral and fatigue life computations in the incremental plasticity analysis of large scale yielding by p-version of F.E.M.

Woo, Kwang S.,Hong, Chong H.,Basu, Prodyot K. Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.17 No.1

Since the linear elastic fracture analysis has been proved to be insufficient in predicting the failure of strain hardening materials, a number of fracture concepts have been studied which remain applicable in the presence of plasticity near a crack tip. This work thereby presents a new finite element model to predict the elastic-plastic crack-tip field and fatigue life of center-cracked panels(CCP) with ductile fracture under large-scale yielding conditions. Also, this study has been carried out to investigate the path-dependence of J-integral within the plastic zone for elastic-perfectly plastic, bilinear elastic-plastic, and nonlinear elastic-plastic materials. Based on the incremental theory of plasticity, the p-version finite element is employed to account for the accurate values of J-integral, the most dominant fracture parameter, and the shape of plastic zone near a crack tip by using the J-integral method. To predict the fatigue life, the conventional Paris law has been modified by substituting the range of J-value denoted by ${\Delta}J$ for ${\Delta}K$. The experimental fatigue test is conducted with five CCP specimens to validate the accuracy of the proposed model. It is noted that the relationship between the crack length a and ${\Delta}K$ in LEFM analysis shows a strong linearity, on the other hand, the nonlinear relationship between a and ${\Delta}J$ is detected in EPFM analysis. Therefore, this trend will be depended especially in the case of large scale yielding. The numerical results by the proposed model are compared with the theoretical solutions in literatures, experimental results, and the numerical solutions by the conventional h-version of the finite element method.

A New Cultivar of the Hardy Kiwifruit, "Chil-Bo", with Large Fruit and High Productivity

Yong Seok Jang,Moon Ho Lee,Byung Sil Lee,Suk In Hwang 한국육종학회 2007 한국육종학회지 Vol.39 No.3

Hardy Kiwifruit (A. arguta (Sieb. & Zucc.) Planch. ex Miq.) is one of the valuable species due to their edible fruits, high content of nutritious substances, especially abundant of vitamin C, and distinctive flavor and medicinal usage. Therefore, we have developed a new cultivar of A. arguta with large fruits and high yielding. For this, 168 candidate plants were collected from wild population in 12 locations from 4 provinces (Chungbuk, Gangwon, Gyeongnam, and Jeonbuk) from 1985 to 1987. A clone bank that contained highly productive, superior genotypes of A. arguta was assembled in 1988, and 32 excellent clones were selected in 1996 through clone tests for growth and fruiting. From these clones, we have regularly investigated yield trials for the fruiting characteristics for evaluation of major agronomic traits, which are the average of Fruit Length (FL), Fruit Width (FW), Weight of Fruit (WF) and Individual Yield (IY), during consecutive 6 years (1997~2002). Finally, we have selected the new A.arguta cultivar, “Chil-Bo” with large fruits and high yielding and registered as a new variety denomination and certificated for variety production and merchandising in 2006 (Table 1). This cultivar is characterized by a tetraploid plant and spheroid type in the fruit shape, and is particularly characterized by large fruit size (Fig. 1). The major agronomic traits of this cultivar showed the large selection effect with an average of 28.4 mm (FL), 36.9 mm (FW), 18.2 g (WF), and 24.2 kg (IY), which are -12.1%, 22.6%, 12.4%, and 210.3% compared to the mean of 29 sample trees, respectively (Table 2).

Seismic Behavior of Steel Frames Equipped with Comb-Teeth Metallic Yielding Dampers

S. Garivani,A. A. Aghakouchak,S. Shahbeyk 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

Comb-teeth damper (CTD), is a new type of metallic yielding damper, which is made of steel plates and includes a number of teeth that dissipate energy through in-plane fl exural yielding. The behavior of individual samples of CTD have been previously studied numerically and experimentally and it has been shown that this damper has excellent energy dissipating capacity and large ductility ratio. In this paper, application of this type of damper to steel frames is studied. Sample steel frames are constructed and equipped with CTDs and tested under cyclic loading. The results show that these dampers can serve their intended duties and dissipate considerable amount of energy. Numerical modelling of the frames confi rms the experimental results and shows that by correct proportioning of the members, frame members i.e. beams, columns and braces remain elastic during lateral loading. This allows using the CTDs as a replaceable energy dissipating device. Finally CTDs are included in a reference frame and their eff ects on reducing seismic demand are studied using non-linear time history analysis. The results show that by using a smaller volume of steel in CTD dampers compared to traditional TADAS, the same level of response reduction may be achieved, while utilizing economic advantage of this type of damper.

변단면 단일 현장타설말뚝의 소성힌지 영향분석

안상용(Ahn Sangyong),정상섬(Jeong Sangseom),김재영(Kim Jaeyoung) 대한토목학회 2010 대한토목학회논문집 C Vol.30 No.3

본 연구에서는 말뚝재료의 항복거동 및 기하학적 비선형 거동인 P-△ 효과를 고려한 변단면 단일 현장타설말뚝의 거동특성을 분석하였다. 이를 위하여 실제 시공된 현장타설말뚝에 대한 말뚝재료의 균열 휨모멘트 및 균열 수평하중을 산정하였고, 국내 · 외에서 적용하고 있는 대표적인 수평변위 기준과의 비교분석을 수행하였다. 또한 구조적 특성을 파악하기 위하여 설계자료를 토대로 재료 및 지반조건을 반영한 현장타설말뚝의 거동을 예측하여 변단면 설계의 타당성을 검토하였다. 분석 결과, 재료의 항복거동과 P-△ 효과 고려시, 이를 고려하지 않는 경우와 비교하여 최대 모멘트가 지표면 부근에서 발생하여 소성힌지 위치에 영향을 주는 것을 나타났으며, 말뚝의 재료파괴는 주로 기둥부의 단면적이 작은 말뚝-기둥 접합부에서 발생하는 것을 알 수 있었다. 또한 주로 말뚝이 수평변위 기준에 도달하기 전에 재료의 파괴가 먼저 발생하기 때문에 말뚝의 항복효과를 고려해야 함을 알 수 있었다. 본 연구 결과, 변단면 단일 현장타설말뚝의 설계 시 불확실성을 고려하여 지지력을 과소 평가하고 있는 것으로 나타났으며, 말뚝재료의 항복거동 및 기하학적 비선형 거동인 P-△ 효과를 고려한 해석기법을 통하여 거동특성을 정확히 예측한다면 경제적인 설계가 가능할 것으로 판단되었다. In this study, the behavior of Pile-Bent structure with varying diameters subjected to lateral loads were evaluated by a load transfer approach. An analytical method based on the beam-column model and nonlinear load transfer curve method was proposed to consider material non-linearity (elastic, yielding) and P-△ effect. For an effective analysis of behavior Pile-Bent structure, the bending moment and fracture lateral load of material were evaluated. And special attention was given to lateral behavior of Pile-Bent structures depending on reinforcing effect of materials and ground conditions. Based on the parametric study, it is shown that the maximum bending moment is located within a depth (plastic hinge) approximately 1~3D (D: pile diameter) below ground surface when material non-linearity and P-△ effect are considered. And distribution of the lateral deflections and bending moments on a pile are highly influenced by the effect of yielding. It is also found that this method considering material yielding behavior and P-△ effect can be effectively used to perform the preliminary design of Pile-bent structures.

인삼 수량과 토양의 물리적 특성을 이용한 재배적지 기준 설정

현동윤,현근수,연병열,강승원,김영철,이광원,김성민 韓國藥用作物學會 2009 한국약용작물학회지 Vol.17 No.6

The purpose of this study was to identify soil physical characteristics as guideline for high yield potential inginseng cultivated field which produced 6 years root. Harvest yields of ginseng to be divided by parent rock was in order ofphyllite and red shale 3.1㎏/3.3㎡ > granite and gneiss·schist 3.0㎏ > basalt 2.6㎏ > porphyry 2.2㎏ in upland and forestsoil. Also, with classified by topography, it was in order of foot slope and alluvial fan 3.2㎏/3.3㎡ > valley 3.0㎏ > low hill2.9㎏ > hill, lave flow and dilluvial terrace 2.8㎏ in survey tilth. Class determination of soil texture, it was in order of sandyloam 3.1㎏/3.3㎡ > loam and silt loam 3.0㎏ > clay loam 2.9㎏ > silt clay loam 2.8㎏ in survey tilth. Slope condition offarming land, in case of sloping (2~7%), it was 3.1㎏/3.3㎡ but deep sloping (15~30%) caused decreasing harvest yield. Indrainage classes (excessively, well and moderately well), there was no significantly different in harvest yields. Relationshipbetween harvest yield and soil series, Production sites as yielding 3.0㎏/3.3㎡ were seven sites, also it was contained 14 soilseries. Production sites as yielding 2.5~3.0㎏/3.3㎡ were eleven sites, it was contained 16 soil series. Production sites asyielding 2.0~2.5㎏/3.3㎡ were 10 sites, it was contained 4 soil series.

세립형 고강도 구조용 강재를 이용한 압축재의 실험적 평가

김요숙,임성우,장인화 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

As for the experimental check, stub and long column tests were carried out. Comparison tests for local and global buckling strength evaluation of box-type and H-shaped welded columns were performed with variable width-thickness ratio. Two kinds of steels were used for tests: High strength steel as a material with yield plateau and same grade steel as a material with continuous yielding. All of the specimens were satisfied with design codes regardless of exceeding the design limits. It means that the current width-thickness ratios may apply to both of the material with yield plateau and that with continuous yielding.

A New Early-Heading and High-Yielding Forage Oat Cultivar, “Highspeed”

Hyoung Ho Park,Hwa Young Heo,Jung Gon Kim,Ki Hun Park,Jae Seong Choi,Young Up Kwon,Jung Hyun Nam,Jung Jun Lee,Choon Ki Lee,In Mo Ryu,Seo Bong Ko,Kwang Yong Jung,Seong Hee Lee 한국육종학회 2006 한국육종학회지 Vol.38 No.4

A new oat (Avena sativa L.) cultivar, “Highspeed” was developed by Honam Agricultural Research Institute (HARI) in 2005. It was released because of its earliness, high forage yield potential, and good adaptability for late summer sowing. “Highspeed” was selected from the mutants of “Olgwiri” irradiated by 250 Gray of γ-ray emitted from ⁶⁰Co in 1998. Subsequent generations were handled in bulk breeding method and M3 was handled in pedigree breeding method. The line, “OlgwiriM250-B- 268”, was selected for earliness and good agronomic characteristics and designated as “Gwiri48” and finally named as ‘Highspeed’. Over 3 years of regional yield trial, “Highspeed” averaged 6.3 MT/ha in forage production as dry matter when sowed in mid August and harvested in early November. It was superior to the check variety, “Swan” with an 34% of yield-increase. Heading date was October 23 which was 6 days earlier than that of “Swan”. “Highspeed” would be recommended as a summer-sowing oat for producing forage just before winter in Korea.