• Title/Summary/Keyword: yield force

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Measurement of mechanical properties of SU-8 thin film by tensile testing (단축 인장에 의한 SU-8박막의 기계적 물성 측정)

  • 백동천;박태상;이순복;이낙규
    • Journal of the Semiconductor & Display Technology
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    • v.3 no.2
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    • pp.23-26
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    • 2004
  • Thin film is one of the most general structures used in micro-electro-mechanical systems (MEMS). To measure the mechanical properties of SU-8 film, tensile testing was adopted which offers not only elastic modulus but also yield strength and plastic deformation by load-displacement curve. Tensile testing system was constructed with linear guided servo motor for actuation, load cell for force measurement and dual microscope for strain measurement.

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Axisymmetric Multi-Stage Deep Drawing Dies Design Analysis Using Finite Element Method (유한요소법을 이용한 축대칭 다단계 딥드로잉 금형 설계 해석)

  • 이동호;금영탁
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.06a
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    • pp.65-73
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    • 1998
  • The design analysis of axisymmetric, multi-stage deep drawing dies was performed using the rigid-viscoplastic finite element formulation. In the formulation, the axisymmetric CFS algorithm was employed. Hill's non-quadratic normal anisotropic yield criterion and isotropic hardening rule were considered. For trial initial displacements and tool contact points, the geometric force equilibrium method was adopted. In order to see the validity of the formulation, the multi-stage deep drawing processes of shell-cylinder front part of hydraulic booster were simulated. The simulation showed good agreements with measurements and PAM-STAMP.

Difference analysis of the collapse behaviors of the single-story beam-column assembly and multi-story planar frame

  • Zheng Tan;Wei-Hui Zhong;Bao Meng;Xing-You Yao;Yu-Hui Zheng;Yao Gao;Shi-Chao Duan
    • Steel and Composite Structures
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    • v.50 no.3
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    • pp.265-280
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    • 2024
  • The collapse behavior observed in single-story beam-column assembly (SSBCA) do not accurately represent the actual overall stress characteristic of multi-story frame structure (MSFS) under column loss scenario owing to ignoring the interaction action among different stories, leading to a disconnection between the anti-collapse behaviors of "components" and "overall structures", that is, the anti-collapse performance of frame structures with two different structural scales has not yet formed a combined force. This paper conducts a numerical and theoretical study to explore the difference of the collapse behaviors of the SSBCA and MSFS, and further to reveal the internal force relationships and boundary constraints at beam ends of models SSBCA and MSFS. Based on the previous experimental tests, the corresponding refined numerical simulation models were established and verified, and comparative analysis on the resistant-collapse performance was carried out, based on the validated modeling methods with considering the actual boundary constraints, and the results illustrates that the collapse behaviors of the SSBCA and MSFS is not a simple multiple relationship. Through numerical simulation and theoretical analysis, the development laws of internal force in each story beam under different boundary constraints was clarified, and the coupling relationship between the bending moment at the most unfavorable section and axial force in the composite beam of different stories of multi story frames with weld cover-plated flange connections was obtained. In addition, considering the effect of the yield performance of adjacent columns on the anti-collapse bearing capacities of the SSBCA and MSFS during the large deformation stages, the calculation formula for the equivalent axial stiffness at the beam ends of each story were provided.

Effect of Planting Density on Growth and Quality in Hydroponics of Sedum sarmentosum (돌나물 수경재배에서 재식밀도에 따른 생육 및 품질 특성)

  • Lee, Seung-Yeob;Kim, Hyo-Jin;Bae, Jong-Hyang
    • Horticultural Science & Technology
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    • v.28 no.4
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    • pp.580-584
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    • 2010
  • The effect of planting densities on the growth of $Sedum$ $samentosum$ (4 collections) was investigated using nutrient film technique (NFT) with Yamazaki' lettuce nutrient solution (1982) from September 5th to October 24th in non-heating plastic film house. At 40 days, the plant height of 4 collections showed the range of 15.0-18.9 cm, and mean plant height was high the order of $10{\times}10$, $2.5{\times}2.5$, and $5{\times}5cm$. The growth of 'Pohang' and 'Wando' collections was better compared to that of 'Gunsan' and 'Wanju' collections. Number of node, stem diameter, and fresh and dry weight per plant were decreased in higher planting density. Despite the lower fresh weight per plant obtained, the fresh yield per $m^2$ was significantly increased in higher planting density. The mean fresh yield was $14.9kg{\cdot}m^{-2}$ in $2.5{\times}2.5cm$, and 'Pohang' collection showed the highest fresh yield ($17.6kg{\cdot}m^{-2}$). The first optimized harvesting time base on plant height was 30-40 days after NFT culture during autumn season. In eating quality, compression force of stem and bitterness of shoot were decreased in higher planting density. However, the heavy labor demanding high density cutting needs to be improved for hydroponic culture of $S.$ $samentosum$.

Pull-out Test of Steel Pipe Pile Reinforced with Hollow Steel Plate Shear Connectors (유공강판 전단연결재로 보강된 강관말뚝 머리의 인발실험)

  • Lee, Kyoung-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.285-291
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    • 2016
  • The purpose of this study was to evaluate the structural capacity of steel pipe pile specimens reinforced with hollow steel plate shear connectors by pull-out test. Compressive strength testing of concrete was conducted and yield forces, tensile strengths and elongation ratios of re-bars and hollow steel plate were investigated. A 2,000kN capacity UTM was used for the pull-out test with 0.01mm/sec velocity by displacement control method. Strain gauges were installed at the center of re-bars and hollow steel plates and LVDTs were also installed to measure the relative displacement between the loading plate and in-filled concrete pile specimens. The yield forces of the steel pipe pile specimens reinforced with hollow steel plate shear connectors were increased 1.44-fold and 1.53-fold compared to that of a control specimen, respectively. Limited state forces of steel pipe pile specimens reinforced with hollow steel plate shear connectors were increased 1.23-fold and 1.29-fold compared to that of a control specimen, respectively. Yield state displacement and limited state displacement of steel pipe pile specimens reinforced with hollow steel plate shear connector were decreased 0.61-fold and 0.42-fold compared to that of a control specimen, respectively.

DEVELOPMENT OF A PERSIMMON HARVESTING SYSTEM

  • Kim, S. M.;Park, S. J.;Kim, C. S.;Kim, M. H.;Lee, C. H.;J. Y. Rhee
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11b
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    • pp.472-479
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    • 2000
  • A persimmon harvesting vehicle that can be operated in hilly orchards as well as a manipulator that can be used to harvest persimmons located in remote positions in the trees were designed and developed. The vehicle could be operated with keeping balanced position in an inclined field and its working platform could be moved up and down easy to approach fruits in a remote region with the aids of a hydraulic and a electrical and electronics systems. The weight of the vehicle was 927 kg and the center of gravity was located at 427 mm to the inner side from the center of a right driving caterpillar, 607 mm to a rear axle from the center of a front axle, and 562 mm to upward from ground. The automatic level control sensor for leveling the working platform was activated within 14.5 ∼ 16.5 degrees of slope variation. The total length of the manipulator was 1.39 m and weight is 975 g. It was powered by a 12 V geared motor to detach persimmon fruits with a rotational force. The gripper was made of plastic and rubber to increase a frictional force. In a performance evaluation test, static tipping angle, dynamic tipping angle toward front side when the vehicle was moving downward, climbing angle, driving speed of the vehicle were measured or calculated. In persimmon harvesting tests 24.9% of yield was increased by hand picking with the aid of the vehicle and additional 7% of yield were increased when the manipulator was used. Therefore, 99010 of total possible yield was achievable when both of the vehicle and the manipulator were used for the manual persimmon harvesting. Increase in 22.5% of total yield was achieved with the manipulator only.

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Alkaline Pilot Processing for Recovery of Fish Muscle Protein and Properties of Recovered Protein (어육 단백질 회수를 위한 알칼리 Pilot 공정과 회수 단백질의 특성)

  • Jang, Young-Boo;Kim, Gun-Bae;Lee, Keun-Woo;Choi, Yeung-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.8
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    • pp.1045-1050
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    • 2006
  • Optimum operation condition for pilot scale of alkaline processing for fish muscle was investigated by measuring protein solubility, yield, texture, and water-holding capacity. Recovered protein yield was 33.2% for whole fish and 61.8% for minced muscle. Optimum homogenized speed and time, using industrial scale homogenizer, were 3,000 rpm and 5 min, respectively. Limited centrifugal force of continuous cylinder type was 4,000 rpm for recovering soluble protein, and 2,000 rpm for recovering precipitated proteins. The pH control agents such as citric acid, sodium phosphate and calcium oxide decreased the breaking force and deformation of recovered protein gel. The breaking force and deformation of the recovered proteins were high compared to conventional surimi. The breaking force and deformation were decreased by addition of salt, starch and bovine plasma proteins. Whiteness of recovered protein gel was lower than that of conventional surimi. Alkaline processing greatly decreased nitrogen content and chemical oxygen demand in waste water. The results suggest that alkaline processing has a potential as industrial production for recovering the proteins from fish muscle.

A Study on the Behavior Characteristics of Large Deep Foundations (대형 깊은 기초의 지지거동 특성에 관한 연구)

  • Park, Choon-Sik;Jung, Kwang-Min
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.1
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    • pp.83-91
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    • 2020
  • In this study, the characteristics of support behavior according to the change of ground condition of the cast-in-place pile and the large Caisson foundation, which are increasingly used as foundations of large structures and bridges. the allowable bearing capacity calculated using the yield load analysis method was analyzed to calculate similar allowable bearing capacity for each method. In addition, the allowable bearing capacity calculated by the ultimate load analysis method was found to have a large difference in bearing capacity for each method. Through this point, it can be usefully used as an empirical formula for evaluating the settlement characteristics of piles in future design and construction. In addition, as a result of examining the ground force distribution during sedimentation of large caissons, the section of the weathered rock layer showed almost constant ground force distribution as ground forces decreased after yield occurred at the base corner. And in the bed rock layer section, the foundation's center was transformed into a ground force in the form of a convex downward due to an increase in the ground resistance of the central part. Using these results, the theory previously presented by Fang (1991) and Kőgler (1936) was proved.

Structural Properties of High-Strength and Low-Yield-Steel Beam-Column for High-Rise Architecture Structure (건축구조용 저항복 고장력강 Beam-Column의 구조특성)

  • Kim, Jong-Sung;Meng, Ming Hua
    • Journal of Korean Society of Steel Construction
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    • v.24 no.1
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    • pp.13-21
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    • 2012
  • Recently, the development of high-strength thicker steel plate above 600MPa is becoming active due to the increase in both height and member size of architectural structure. However, such steel, which is being investigated in Korea nowadays, has possibility of limited practical application because of high design code strength and high-yield ratio. Therefore, this study performed the validation for the structural performance of beam-column with combined axial force and bending moment whether this beam-column might be attributable as an architectural purpose steel. This study was conducted from the result of monotonic loading test of beam-column, based on the material properties of low-yield, 600MPa class steel which was developed during 1988-1993 in Japan. This study might provide the fundamental database for practical research for these steel which are actively being tested in Korea.

Development of Restructured Chicken Thigh Jerky Added with Red Pepper Seed Powder (고추씨 분말을 첨가한 닭다리살 재구성 육포 개발)

  • Lee, Jeong-Ah;Kim, Hack-Youn
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.9
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    • pp.1333-1337
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    • 2016
  • This study aimed to investigate the effects of red pepper seed powder on the physicochemical properties (pH, CIE color value, water holding capacity, dry yield, proximate composition, and shear force) of restructured chicken thigh jerky. The restructured chicken thigh jerky samples were prepared with the following amounts of red pepper seed powder [0% (control), 1%, 2%, and 3%]. Moisture contents of samples containing red pepper seed powder were significantly higher than those of control (P<0.05). The lightness, redness, and yellowness of samples an increased with an increase in red pepper seed powder. Water holding capacity and dry yield of samples increased with increasing concentration of red pepper seed powder. However, shear force of samples showed a downward trend with increasing red pepper seed powder level. The sensory evaluation of samples containing 3% red pepper seed powder were highest. The results indicate that red pepper seed powder could be enhance the physicochemical properties of restructured chicken thigh jerky.