• Title/Summary/Keyword: strip load

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A Study on the Development of Reinforced Earth wall by Geotextile (토목섬유를 이용한 보강토옹벽의 개발)

  • 도덕현;유능환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.63-73
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    • 1986
  • The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

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Pressure loading, end- shortening and through- thickness shearing effects on geometrically nonlinear response of composite laminated plates using higher order finite strip method

  • Sherafat, Mohammad H.;Ghannadpour, Seyyed Amir M.;Ovesy, Hamid R.
    • Structural Engineering and Mechanics
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    • v.45 no.5
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    • pp.677-691
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    • 2013
  • A semi-analytical finite strip method is developed for analyzing the post-buckling behavior of rectangular composite laminated plates of arbitrary lay-up subjected to progressive end-shortening in their plane and to normal pressure loading. In this method, all the displacements are postulated by the appropriate harmonic shape functions in the longitudinal direction and polynomial interpolation functions in the transverse direction. Thin or thick plates are assumed and correspondingly the Classical Plate Theory (CPT) or Higher Order Plate Theory (HOPT) is applied. The in-plane transverse deflection is allowed at the loaded ends of the plate, whilst the same deflection at the unloaded edges is either allowed to occur or completely restrained. Geometric non-linearity is introduced in the strain-displacement equations in the manner of the von-Karman assumptions. The formulations of the finite strip methods are based on the concept of the principle of the minimum potential energy. The Newton-Raphson method is used to solve the non-linear equilibrium equations. A number of applications involving isotropic plates, symmetric and unsymmetric cross-ply laminates are described to investigate the through-thickness shearing effects as well as the effect of pressure loading, end-shortening and boundary conditions. The study of the results has revealed that the response of the composite laminated plates is particularly influenced by the application of the Higher Order Plate Theory (HOPT) and normal pressure loading. In the relatively thick plates, the HOPT results have more accuracy than CPT.

The Earth Pressure on the Effect of Surcharge Load at the Narrowly Backfilled Soil (좁은 공간 되메움 지반에서의 상재하 영향에 의한 토압)

  • 문창열;이종규
    • Geotechnical Engineering
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    • v.13 no.6
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    • pp.165-180
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    • 1997
  • The structure such as underground external walls of buildings, conduit and box culvert supports the surcharge loads (point, strip and line loads) . The vertical and horizontal stresses in a soil mass depend on the backfill width and wall friction, etc. The investigations described in this paper is designed to identify the magnitude and the distributions of the lateral and vertical pressure which is occurred by the narrowly backfilled soil in an open cut by the surcharge loads. For these purposes, model tests were performed for various width of backfill in a model test box by considering the wall friction using carbon rods. The results of test were compared with the theories of Weissenbach and VS Army Code and also with the results of the numerical analysis using finite difference method which introduces Mohr-Coulomb failure hypothesis.

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Generation & Application of Nonlinear Wave Loads for Structural Design of Very Large Containerships (초대형 컨테이너선 구조 설계를 위한 비선형 파랑하중 생성 및 적용)

  • Jung Byoung Hoon;Ryu Hong Ryeul;Choi Byung Ki
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.15-21
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    • 2005
  • In this paper, the procedure of generation and application of nonlinear wave loads for structural design of large container carrier was described. Ship motion and wave load was calculated by modified strip method. Pressure acting on wetted hull surface was calculated taking into account of relative hull motion to the wave. Design wave height was determined based on the most sensitive wave length considering rule vertical wave bending moment at head sea or fellowing sea condition. And the enforced heeling angie concept which was introduced by Germanischer Lloyd (GL) classification had been used to simulate high torsional moment in way of fore hold parts similar to actual sea going condition. Using wave load generated from this dynamic load calculation, FE analyses were performed. With this result, yielding, buckling, hatch diagonal deflection and fatigue strength of hatch corners were reviewed based on the requirement of GL classification. The results of FE analysis show good compatibility with GL classification.

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Fire Behavior of Steel Columns Encased by Damaged Spray-applied Fire Resistive Material

  • Kwak, Yoon Keun;Pessiki, Stephen;Kwon, Kihyon
    • Architectural research
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    • v.10 no.1
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    • pp.1-11
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    • 2008
  • A Steel column with damaged spray-applied fire resistive material (SFRM) may exhibit reduced structural performance due to the effects of elevated temperature during fire events. Thus, the fire load behavior of steel columns with removed or reduced SFRM needs to be examined to predict the structural damage by fire. FEM analyses were performed for the flange thinning removal models in which the SFRM was reduced as a constant strip in thickness at the top flange of the column. The temperature results for all models obtained from the heat transfer analyses were included as an initial condition in the FEM structural analyses. In this study, the results of analysis show that even small remnants of SFRM led to an effective reduction of temperature at any given fire duration, and improved significantly the axial load capacity of a column as compared to the complete removal cases of SFRM.

Vehicle Load Effects of Flat Slab Parking Structures (플랫 슬래브 주차장 구조물의 차량 하중 영향 연구)

  • 곽효경;이기장;이정원;송종영
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.143-150
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    • 2001
  • In this paper, the effects of vehicle loads on flat slab system are investigated based on the previous studies on beam-girder parking structural system. The influence surfaces of flat slab for typical design section are determined for the purpose of obtaining member forces under vehicle loads. In addition, the equivalent vehicle load factors for flat slab parking structures are suggested using neural network. It has been found that vehicle load effects of flat slab system are dominant for the center positive moment in both column and middle strip, as like beam-girder parking structural system.

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Enhancement of HRSM4BMP Model to Simulate Sediment Reduction Efficiency Based on Watershed Scale (유역단위 유사 저감 효과 모의를 위한 HRSM4BMP모형의 개선)

  • Ryu, Jichul;Kum, Donghyuk;Shin, Dong Seok;Ahn, Ki Hong;Park, Bae Kyung;Lim, Koung Jae
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.8
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    • pp.521-527
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    • 2014
  • The objectives of study are 1) to enhance the filed scale BMPs model of HRSM4BMP for simulation of watershed scale and 2) to evaluate the enhanced HRSM4BMP model. Thus pre-process and post-process module were developed and HRSM4BMP was linked to SWAT routing module. After enhancement of model, enhanced HRSM4BMP model was applied to Heaan watershed in Kangwon province with Vegetative filter strip (2 m) in subwatershed #14 and reduction of sediment load was evaluated by watershed scale in outlet. The results of simulation, sediment load was reduced by 4 percent during 3 years in outlet. The result of this study is expected to be used Long-term BMPs establishing plan in South Korea.

Dynamics of the oscillating moving load acting on the hydroelastic system consisting of the elastic plate, compressible viscous fluid and rigid wall

  • Akbarov, Surkay D.;Ismailov, Meftun I.
    • Structural Engineering and Mechanics
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    • v.59 no.3
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    • pp.403-430
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    • 2016
  • This paper studies the dynamics of the lineal-located time-harmonic moving-with-constant-velocity load which acts on the hydro-elastic system consisting of the elastic plate, compressible viscous fluid - strip and rigid wall. The plane-strain state in the plate is considered and its motion is described by employing the exact equations of elastodynamics but the plane-parallel flow of the fluid is described by the linearized Navier-Stokes equations. It is assumed that the velocity and force vectors of the constituents are continuous on the contact plane between the plate and fluid, and impermeability conditions on the rigid wall are satisfied. Numerical results on the velocity and stress distributions on the interface plane are presented and discussed and the focus is on the influence of the effect caused by the interaction between oscillation and moving of the external load. During these discussions, the corresponding earlier results by the authors are used which were obtained in the cases where, on the system under consideration, only the oscillating or moving load acts. In particular, it is established that the magnitude of the aforementioned interaction depends significantly on the vibration phase of the system.

Motion and pin Wave Load characteristics of Ocean Going Pusher-Barge in Regular Waves (Pusher-Barge선의 내항성능 및 연결핀에 작용하는 피랑하중추정)

  • Hong, Seok-Won;Kim, Yeong-Hwan
    • 한국기계연구소 소보
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    • s.12
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    • pp.49-61
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    • 1984
  • 대양을 항해하는 Puser-Barge선의 내항성능과 그연결장치에 작용하는 피랑하중을 추정하기위하여,규칙피중 선체운동응답과,파랑하중응답을 Strip이론으로 구하는 해석적인 방법을 개발하였다. 연결장치의 종류로는 2개의 핀으로 연결되는 힌지연결의 경우와, 3개의 핀으로 연결되는 고정연결의 경우를 고려하였다. 이론 계산결과를 확인하기 위한 모형시험을 힌지연결의 경우에 대하여 정면규칙파중에서 실시하였다. 실험결과와 이론계산결과는 비교적 잘 일치하였다.

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An accurate approach for buckling analysis of stringer stiffened laminated composite cylindrical shells under axial compression

  • Davood Poorveis;Amin Khajehdezfuly;Mohammad Reza Sardari;Shapour Moradi
    • Steel and Composite Structures
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    • v.51 no.5
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    • pp.543-562
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    • 2024
  • While the external axial compressive load is applied to only the shell edge of stringer-stiffened shell in the most of numerical and analytical previous studies (entitled as conventional approach), a part of external load is applied to the stringers in real conditions. It leads to decrease the accuracy of the axial buckling load calculated by the conventional eigenvalue analysis approach performed in the most of previous studies. In this study, the distribution of stress in the pre-buckling analysis was enhanced by applying the axial external compressive load to both shell and stringers to perform an accurate eigenvalue analysis of the stringer-stiffened composite shell. In this regard, a model was developed in FORTRAN environment to simulate the laminated stringer-stiffened shell under axial compressive load using finite strip method. The axial buckling load of the shell was obtained through eigenvalue analysis. A comparison was made between the results obtained from the model and those available in the previous studies to evaluate the validity of the results obtained from the model. Through a parametric study, the effects of different parameters such as stringer properties and composite layup on the buckling load of the shell under different loading patterns were investigated. The results indicated that in some cases, the axial buckling load obtained for the conventional approach used in the most of previous studies is significantly overestimated or underestimated due to neglecting the stringer in distribution of external load applied to the stringer-stiffened shell. According to the results obtained from the parametric study, some graphs were derived to show the accuracy of the axial buckling load obtained from the conventional approach utilized in the literature.