• Title, Summary, Keyword: displacement distribution

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Study on Relationship of Flexural Moment-Curvature Based on Bond Property of Reinforced Concrete Member (철근콘크리트 부재의 부착특성을 고려한 휨모멘트-곡률 관계에 관한연구)

  • 장일영
    • Magazine of the Korea Concrete Institute
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    • v.3 no.4
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    • pp.97-106
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    • 1991
  • The object of this study is to propose the Flexural moment-curvature relationship based on the bond property between concrete and steel for noncracking zone, to evaluate the flexural displacement of reinforced concrete member. The bond-slip relationship and the strain hardening effect of steel were taken into consideration in order to evaluate the spacing of the cracks and the curvature distribution. Calculated curvature distribution along the longitudinal axis was transformed into equivalent curvature distribution. The flexural displacement was calculated by means of double integrals of the equivalent curvature. Furthermore, 34 beams were tested in order to verify the proposed procedure Calculated values agreed well with the experimental data, and so it is pointed out that proposed method is widely acceptable for the practical evaluation of flexural displacement of reinforced concrete member.

Application of shear deformation theory for two dimensional electro-elastic analysis of a FGP cylinder

  • Arefi, M.;Rahimi, G.H.
    • Smart Structures and Systems
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    • v.13 no.1
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    • pp.1-24
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    • 2014
  • The present study deals with two dimensional electro-elastic analysis of a functionally graded piezoelectric (FGP) cylinder under internal pressure. Energy method and first order shear deformation theory (FSDT) are employed for this purpose. All mechanical and electrical properties except Poisson ratio are considered as a power function along the radial direction. The cylinder is subjected to uniform internal pressure. By supposing two dimensional displacement and electric potential fields along the radial and axial direction, the governing differential equations can be derived in terms of unknown electrical and mechanical functions. Homogeneous solution can be obtained by imposing the appropriate mechanical and electrical boundary conditions. This proposed solution has capability to solve the cylinder structure with arbitrary boundary conditions. The previous solutions have been proposed for the problem with simple boundary conditions (simply supported cylinder) by using the routine functions such as trigonometric functions. The axial distribution of the axial displacement, radial displacement and electric potential of the cylinder can be presented as the important results of this paper for various non homogeneous indexes. This paper evaluates the effect of a local support on the distribution of mechanical and electrical components. This investigation indicates that a support has important influence on the distribution of mechanical and electrical components rather than a cylinder with ignoring the effect of the supports. Obtained results using present method at regions that are adequate far from two ends of the cylinder can be compared with previous results (plane elasticity and one dimensional first order shear deformation theories).

Analysis of displacement behavior in fractured fault and groundwater flow under tunnel excavation (터널굴착중 굴착면 단층파쇄대와 지하수 용출 구간에서 단계별 변위 거동 특성 분석)

  • Kim, Nag-Young;Park, Gun-Tae;Baek, Seung-Cheol;Lee, Kang-Hyun;Choi, Jin-Woong;Her, Yol
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.1
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    • pp.71-82
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    • 2017
  • It is necessary to conduct a detailed geotechnical investigation on the tunnel section in order to secure the tunnel design and construction stability. It is necessary for the importance of geotechnical investigation that needed for the analysis of distribution and size of fractured fault zone and distribution of groundwater in tunnel. However, if it is difficult to perform the ground survey in the tunnel design due to ground condition of the tunnel section and the limited conditions such as civil complaint, the tunnel design is performed using the result of the minimum survey. Therefore, if weathered fault zone exists in the face the reinforcement method is determined in the design process to secure the stability of the tunnel. The most important factor in reinforcing the tunnel excavation surface is to secure the stability of the tunnel by performing quick reinforcement. In particular, if groundwater leaching occurs on the excavation surface, more rapid reinforcement is needed. In this study, fractured fault zone exists on the tunnel excavation surface and displacement occurs due to weathered fracture zone. When the amount of groundwater leaching rapidly increased under the condition of displacement, the behavior of tunnel displacement was analyzed based on tunnel collapse. In the study, reinforcement measures were taken because the first stage displacement did not converge continuously. After the first reinforcement, the displacement was not converged due to increased groundwater leaching and the second stage displacement occurred and chimney collapse occurred.

The Effect of the DIC Speckle Patterns for a Microcrack Measurement (미소균열 측정에 대한 DIC 스펙클 형상의 영향)

  • Lee, Jun Hyuk;Kwon, Oh Heon
    • Journal of the Korean Society of Safety
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    • v.34 no.4
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    • pp.15-21
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    • 2019
  • In order to secure the safety of various machinery, it is very important to develop a technique for accurately and quickly measuring the cracks generated in the mechanical equipment and evaluating the mechanical characteristics. The evaluation of the mechanical properties is accompanied by an appropriate strain measurement according to the material and crack occurrence of the target structure. Especially, when micro cracks are generated, the evaluation method is very important. Digital image correlation is an optical full field displacement measuring method which is using currently with speckles in the interested area. However the evaluation method and conditions of image distributions have to be considered carefully to measure the crack occurrence because the images of the speckle patterns affect the quality of displacement results. In this study, the speckle pattern density is characterized to improve the accuracy of the measurement method. And also the micro crack initiation is detected by the measured displacement in the adopted speckle pattern distribution. It is shown that the proposed method is useful to determine the density pattern distribution for the accurate measurement and crack detection.

FINITE ELEMENT STRESS ANALYSIS OF FIXED PARTIAL DENTURE SUPPORTED BY THE ABUTMENT WITH REDUCED ALVEOLAR BONE (치조골이 감소된 지대치를 이용한 고정성 국소의치의 유한요소법적 응력분석)

  • Kim, Young-Gi;Choi, Choong-Kug;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.1
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    • pp.32-47
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    • 1995
  • The purpose of this study was to determine the displacement of prosthesis & abutment and the stress distribution patterns induced in the periodontium by applying force to the fixed prosthesis. Two levels of periodontal support were compared using two-dimensional finite element stress analysis after placement of 3unit or 4 unit fixed partial denture(FPD) in case of missing of the lower first molar. Concentrated vertical load was delivered at the cusp tip of the second bicuspid or the central fossa of the pontic. The following results were obtained : 1. The greater the loss of alveolar bone in abutment teeth area, the greater the displacement of FPD and the stress concentration in alveolar bone around abutment. 2. The amount and direction of displacement and distribution of stress in the 4-unit FPD was better than those in the 3-unit FPD. 3. Multiple abutments reduced the amount of mesial and downward displacement of the weaked abutments and more uniformly distributed the stresses.

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Application of Variational Method to the Elastic Foundation (변분법에 의한 탄성지반 해석)

  • Lee, Seung-Hyun;Han, Jin-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4642-4647
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    • 2011
  • Solution for elastic foundation of plane strain state was derived by the application of variational method. Functions of the transverse distribution of the displacements for the analysis were chosen as linear functions. Loading conditions considered for the analysis were concentrated load and distributed load. Under the loading condition of the concentrated load, surface displacement was decreased drastically as the distance from the point of the loading increased. Under the loading condition of the distributed load, surface displacements were more uniformly distributed beneath the loading area when the ratio of the half of the loading width to the depth(B/H) of the compressible layer was greater. The surface displacement was more quickly converged from the edge of the loading area as the ratio(B/H) increased.

Thermal Characteristics Analysis of 30,000rpm High Speed Spindle (30,000rpm 고속 주축의 열특성 분석)

  • Lim, Jeong-Suk;Yu, Ki-Han;Chung, Won-Jee;Kim, Soo-Tae;Lee, Jung-Hwan;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.7
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    • pp.120-126
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    • 2009
  • Thermal displacement of high speed spindle is very important problem to be solved. To solve heat generation and thermal displacement problems that influence on the product accuracy, it is very important to predict thermal characteristics of the spindle and it is positively necessary to select the conditions of cooling, flow rate and preload of bearings. In this paper, 30,000rpm($1.455{\times}10^6DmN$) spindle was designed and produced. The analysis of thermal deformation for heat generation of inner spindle was carried out using commercial program $ANSYS^{(R)}$ and the result was compared with measured data using $LabVIEW^{(R)}$ and SGXI-1600, 1125 and 1126 module. Temperature distribution and thermal displacement according to spindle speed are measured. Using this method, it is possible to predict and to improve thermal characteristic of high speed spindle by control spindle speed, bearing preload and cooling rate.

The Comparison of the Characteristics of Displacement Isolines in the Cylindrical Green Compact under Ultrasonic Vibration

  • Prakorb, Chartpuk;Anan, Tempiam;Somchai, Luangsod;Vorawit, Voranawin
    • International journal of advanced smart convergence
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    • v.4 no.1
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    • pp.120-126
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    • 2015
  • This research is a comparison of the characteristics of the displacement isolines due to powder-die-wall friction that arise during the compaction of ceramic powders in conventional die. It has been done using the CosmosWorks software package of the SolidWorks simulation software. The results of comparative simulation with FEM showed that the comparison of the displacement isolines and distribution of deformation of the ceramic powders. In the case of conventional uniaxial dry compaction for long length cylindrical green compact, considerable bending of the layers in the form of a cone can be observed. It is symmetry along centerline of cylindrical green compact. The distributions of the deformation of the green compacts (diameter 14 mm, height 20 mm) as a result of conventional compaction under ultrasonic vibration with power 1 and 2 kW are reduced to 4% and 6.5% when compared with conventional compaction without ultrasonic vibration respectively. Thus, density distribution can be minimized by increasing the power of ultrasonic vibration.

Studying the nonlinear behavior of the functionally graded annular plates with piezoelectric layers as a sensor and actuator under normal pressure

  • Arefi, M.;Rahimi, G.H.
    • Smart Structures and Systems
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    • v.9 no.2
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    • pp.127-143
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    • 2012
  • The present paper deals with the nonlinear analysis of the functionally graded piezoelectric (FGP) annular plate with two smart layers as sensor and actuator. The normal pressure is applied on the plate. The geometric nonlinearity is considered in the strain-displacement equations based on Von-Karman assumption. The problem is symmetric due to symmetric loading, boundary conditions and material properties. The radial and transverse displacements are supposed as two dominant components of displacement. The constitutive equations are derived for two sections of the plate, individually. Total energy of the system is evaluated for elastic solid and piezoelectric sections in terms of two components of displacement and electric potential. The response of the system can be obtained using minimization of the energy of system with respect to amplitude of displacements and electric potential. The distribution of all material properties is considered as power function along the thickness direction. Displacement-load and electric potential-load curves verify the nonlinearity nature of the problem. The response of the linear analysis is investigated and compared with those results obtained using the nonlinear analysis. This comparison justifies the necessity of a nonlinear analysis. The distribution of the displacements and electric potential in terms of non homogenous index indicates that these curves converge for small value of piezoelectric thickness with respect to elastic solid thickness.

An Experimental Study on the Displacement of Suspension Element for High Speed Rolling-stock (고속철도차량 현가요소 운동변위에 대한 실험적 연구)

  • Kim, Hyung-Jin;You, Won-Hee;Park, Tae-Won;Hur, Hyun-Moo
    • Journal of the Korean Society for Railway
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    • v.9 no.6
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    • pp.798-803
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    • 2006
  • The suspension elements like primary coil spring, yaw damper, body to body damper are core parts of high speed railway bogie and the faults relating to these elements are reported recently. Thus, this study is started to analyze the displacements characteristics of suspension elements of high speed railway rolling-stock for the purpose of preventing the faults and developing the maintenance technology for suspension elements like spring and dampers. For this purpose, we made a plan to measure the displacements of the primary coil spring, yaw damper and body to body damper in actual running condition. We developed the measurement device to measure the longitudinal displacement and angular displacement of suspension elements and installed this device to test suspension elements. Test to measure displacements of suspension elements is conducted in service line of high speed railway. The displacement data which is acquired from the test with actual vehicles was analyzed for its maximum displacement depending on the track sections. As a result of analysis, we obtained the displacement trends occurring with the sections and valuable results like maximum values and the displacement distribution.