• Title/Summary/Keyword: load angle

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Investigation of earthquake angle effect on the seismic performance of steel bridges

  • Altunisik, Ahmet C.;Kalkan, Ebru
    • Steel and Composite Structures
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    • 제22권4호
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    • pp.855-874
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    • 2016
  • In this paper, it is aimed to evaluate the earthquake angle influence on the seismic performance of steel highway bridges. Upper-deck steel highway bridge, which has arch type load bearing system with a total length of 216 m, has been selected as an application and analyzed using finite element methods. The bridge is subjected to 1992 Erzincan earthquake ground motion components in nineteen directions whose values range between 0 to 90 degrees, with an increment of 5 degrees. The seismic weight is calculated using full dead load plus 30% of live load. The variation of maximum displacements in each directions and internal forces such as axial forces, shear forces and bending moments for bridge arch and deck are attained to determine the earthquake angle influence on the seismic performance. The results show that angle of seismic input motion considerably influences the response of the bridge. It is seen that maximum arch displacements are obtained at X, Y and Z direction for $0^{\circ}$, $65^{\circ}$ and $5^{\circ}$, respectively. The results are changed considerably with the different earthquake angle. The maximum differences are calculated as 57.06%, 114.4% and 55.71% for X, Y and Z directions, respectively. The maximum axial forces, shear forces and bending moments are obtained for bridge arch at $90^{\circ}$, $5^{\circ}$ and $0^{\circ}$, respectively. The maximum differences are calculated as 49.12%, 37.37% and 51.50%, respectively. The maximum shear forces and bending moments are obtained for bridge deck at $0^{\circ}$. The maximum differences are calculated as 49.67%, and 49.15%, respectively. It is seen from the study that the variation of earthquake angle effect the structural performance of highway bridges considerably. But, there is not any specific earthquake angle of incidence for each structures or members which increases the value of internal forces of all structural members together. Each member gets its maximum value of in a specific angle of incidence.

예연소실(豫燃燒室)의 형상(形狀)이 농용(農用) 디이젤엔진의 성능(性能)에 미치는 영향(影響) (Effects of Form and Angle of Precombustion Chamber on Performance of Agricultural Diesel Engine)

  • 이욱;이승규;김성태
    • Journal of Biosystems Engineering
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    • 제8권1호
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    • pp.70-74
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    • 1983
  • This study was conducted to determine whether or not the form and angle of the precombustion chamber affected the performance of agricultural diesel engines. Twenty different types of precombustion chambers were designed and tested using a two way classification with four individual tests. The output power and specific fuel consumption ratio at full load were measured and analyzed. The results of the study were summarized as follows; 1. The diameter of main passageway giving the best power output and specific fuel consumption ratio at full load was between 5.8 and 6.1mm. The ratio of area of main passageway bore to that of piston head was from 0.4 to 0.44 percent at the highest engine power. 2. The angle of main passageway giving the best power output and specific fuel consumption ratio at full load was between 41 and 43 degrees. 3. The change of the diameter of main passageway affected the output of engine more significantly than the change of angle, however, on the specific fuel consumption ratio the angle of main passageway had more effect than the diameter.

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비틀어진 형상(Twisted)을 가지는 고층 구조물의 역학적 특성 분석 (Analysis of the Static Characteristics of High-Rise Structures With Twisted Shape)

  • 이다혜;김현수;강주원
    • 한국공간구조학회논문집
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    • 제20권4호
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    • pp.93-100
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    • 2020
  • In this study, structural characteristics were analyzed by combining gravity load and lateral loads such as seismic loads through static analysis of example structures, and the static characteristics of the twisted structure according to the plane rotation angle were also analyzed. Example structures were selected as regular structure, and twisted structures; 1.0, 2.0, and 3.0 degree angle of rotation per story, and static analysis was performed by the load combination case 1 and case 2. As a result the story drift ratio of the twisted-shaped structure also increased as the plane rotation angle per story increased. The eccentricity according to the load combination was the highest in the lower stories of all analysis models, and the eccentricity was found to be larger as the rotation angle decreased. The twisted-shaped structure was more responsible for the bending moment of the column than the regular structure, and the vertical member axial force of all analysis models was almost similar.

보행 시 부하의 위치에 따른 발의 안정성 및 운동학적 분석에 관한 연구 (The Studies on the Foot Stability and Kinesiology by Direction of Carry a Load during Gait)

  • 이상열;배성수
    • The Journal of Korean Physical Therapy
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    • 제21권2호
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    • pp.97-101
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    • 2009
  • Purpose: This study examined how the direction of carrying a load affects the foot stability and kinesiology while walking. Methods: The heel rotation, Hallux stiffness, foot balance, metatarsal load, toe out angle, subtalar joint flexibility were measured in 40 adults (men and women) who carried a load back and forth, walking on a 2-meter-long board. The measurement was carried out three times and the mean of the measurements was used to compare the difference between the front, back and the condition without a load. Results: While walking, heel rotation and hallux stiffness occurred most when a front load was applied compared to a back load or no load condition (p<0.05). A metatarsal load also appeared to be the highest with the frond load, but there was no significant difference in the balance of the whole foot. Both the toe out angle and subtalar joint flexibility appeared to increase significantly (p<0.05). Conclusion: Applying the front load causes subtalar joint instability and increases the plantar foot pressure imbalance during walking.

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Effect of Load Condition on Turning Performance of a VLCC in Adverse Weather Conditions

  • Zaky, Mochammad;Yasukawa, Hironori
    • Journal of Advanced Research in Ocean Engineering
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    • 제4권2호
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    • pp.53-65
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    • 2018
  • The load condition significantly influences ship maneuverability in calm water. In this research, the effect of the load condition on turning performance of a very large crude oil carrier (VLCC) sailing in adverse weather conditions is investigated by an MMG-based maneuvering simulation method. The relative drift direction of the ship in turning to the wave direction is $20^{\circ}-30^{\circ}$ in ballast load condition (NB) and full load condition (DF) with a rudder angle $35^{\circ}$ and almost constant for any wind (wave) directions. The drifting displacement in turning under NB becomes larger than that under DF at the same environmental condition. Advance $A_d$ and tactical diameter $D_t$ become significantly small with an increasing Beaufort scale in head wind and waves when approaching, although $A_d$ and $D_t$ are almost constant in following wind and waves. In beam wind and waves, the tendency depends on the plus and minus of the rudder angle.

지오셀을 적용한 지반의 보강효과에 관한연구 (Effect Reinforced Ground using Geocell)

  • 신은철;김성환;오영인
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.782-791
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    • 2009
  • This study was carried out the laboratory tests and field plate load test in order to evaluate the reinforcement effect of geocell for road construction. The geocell-reinforced subgrade shows the increment of cohesion and friction angle with comprison of non-reinforced subgrade. In addition, the field plate load test was performed on the geocell-reinforced subgrade to estimate the bearing capacity of soil. The direct shear test was conducted with utilizing a large-scale shear box to evaluate the internal soil friction angle with geocell reinforcement. The number of cells in the geocell system is varied to investigate the effect of soil reinforcement. The theoretical bearing capacity of subgrade soil with and without geocell reinforcement was estimated by using the soil internal friction angle. The field plate load tests were also conducted to estimate the bearing capacity with geocell reinforcement. It is found out that the bearing capacity of geocell-reinforced subgrade gives 2 times higher value than that of unreinforced subgrade soil. In the future, the reinforcement effect of the geocell rigidity and load-balancing effect of the geocells should be evaluated.

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비틀림 전방압출 공정의 최적다이각에 관한 연구 (A Study on the Optimal die angle of the Torsional Forward Extrusion Process)

  • 이상인;김영호
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 제5회 압출 및 인발가공 심포지엄
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    • pp.23-32
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    • 2002
  • The torsional forward extrusion is the process that is executed by punch travel and die rotation. The advantages of having the die rotation on this process are that forming load can be reduced and optimal die angle can be increased. This provides a possibility to extrude cold-worded material where a large extrusion force and die angle are required. Also, this process can improve the material properties owing to the high deformation and uniform strain distribution. The forming load and optimal die angle of this process are determined by the upper bound analysis using stream function and the optimization technique. To verify the theoretical result, we have carried out experiments and FE simulations using DEFORM3D.

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Biomechanical Changes of the Lumbar Segment after Total Disc Replacement : Charite$^{(R)}$, Prodisc$^{(R)}$ and Maverick$^{(R)}$ Using Finite Element Model Study

  • Kim, Ki-Tack;Lee, Sang-Hun;Suk, Kyung-Soo;Lee, Jung-Hee;Jeong, Bi-O
    • Journal of Korean Neurosurgical Society
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    • 제47권6호
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    • pp.446-453
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    • 2010
  • Objective : The purpose of this study was to analyze the biomechanical effects of three different constrained types of an artificial disc on the implanted and adjacent segments in the lumbar spine using a finite element model (FEM). Methods : The created intact model was validated by comparing the flexion-extension response without pre-load with the corresponding results obtained from the published experimental studies. The validated intact lumbar model was tested after implantation of three artificial discs at L4-5. Each implanted model was subjected to a combination of 400 N follower load and 5 Nm of flexion/extension moments. ABAQUS$^{TM}$ version 6.5 (ABAQUS Inc., Providence, RI, USA) and FEMAP version 8.20 (Electronic Data Systems Corp., Plano, TX, USA) were used for meshing and analysis of geometry of the intact and implanted models. Results : Under the flexion load, the intersegmental rotation angles of all the implanted models were similar to that of the intact model, but under the extension load, the values were greater than that of the intact model. The facet contact loads of three implanted models were greater than the loads observed with the intact model. Conclusion : Under the flexion load, three types of the implanted model at the L4-5 level showed the intersegmental rotation angle similar to the one measured with the intact model. Under the extension load, all of the artificial disc implanted models demonstrated an increased extension rotational angle at the operated level (L4-5), resulting in an increase under the facet contact load when compared with the adjacent segments. The increased facet load may lead to facet degeneration.

앵커간격 및 하중방향에 따른 앵커의 전단내력 (Shear Strength of Anchors under Load Applied Angle and a Group Anchors at an Edge)

  • 김성용
    • 한국방재학회 논문집
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    • 제3권3호
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    • pp.133-141
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    • 2003
  • 본 연구는 비균열 무근콘크리트에 매입된 앵커의 앵커간격 및 하중방향에 따른 전단내력 평가를 목적으로 하고 있다. 이를 위하여 앵커의 전단내력 설계식을 비교 평가하였으며, 실험값과 기존의 설계식의 예측값을 비교 분석하였다. 그 결과, 앵커간격 및 하중방향에 따른 CCD 방법 및 EOTA 설계식은 합리적인 설계방법임을 알 수 있었다.

TECHNIQUE OF SEPARATE MEASURING SIDE SLIP FOR TOE ANGLE AND CAMBER ANGLE

  • Nozaki, H.
    • International Journal of Automotive Technology
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    • 제7권6호
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    • pp.681-686
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    • 2006
  • The current flat type side slip tester measures only the total side slip. Therefore, measurement techniques which can be used to determine the side slip for each alignment element were examined. Because the side slip related to the camber angle varies depending on the unit load per travel wheel while the side slip related to the toe angle does not on the unit per travel wheel, but depends only on the direction of the tire, the side slip for each alignment element can be determined separately.