• Title/Summary/Keyword: Double-cantilever beam

Search Result 121, Processing Time 0.026 seconds

Influence of Tip Mass and Moving Mass on Dynamic Behavior of Beam with Double-Crack (이중크랙을 가진 보의 동특성에 미치는 끝단질량과 이동질량의 영향)

  • Son, In-Soo;Yoon, Han-Ik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.11a
    • /
    • pp.713-716
    • /
    • 2004
  • In this paper a dynamic behavior of a double-cracked cnatilver beam with a tip mass and the moving mass is presented. Based on the Euler-Bernoulli beam theory, the equation of motion is derived by using Lagrange's equation. The influences of the moving mass, a tip mass and double cracks have been studied on the dynamic behavior of a cantilever beam system by numerical method. The cracks section are represented by the local flexibility matrix connecting two undamaged beam segments. ,Therefore, the cracks are modelled as a rotational spring. Totally, as a tip mass is increased, the natural frequency of cantilever beam is decreased. The position of the crack is located in front of the cantilever beam, the frequencies of a double-cracked cantilever beam presents minimum frequency.

  • PDF

Analysis of Bridging Stress Effect of Polycrystalline Aluminas Using Double Cantilever Beam Method II. Development of Double Cantilever Beam Method Considering Bridging Effect (Double Cantilever Beam 방법을 이용한 다결정 알루미나의 Bridging 응력효과 해서 II. Bridging 효과를 고려한 Double cantilever Beam 분석방법의 정립)

  • 손기선;이성학;백성기
    • Journal of the Korean Ceramic Society
    • /
    • v.33 no.5
    • /
    • pp.590-601
    • /
    • 1996
  • This study aims at developing the double cantilever beam (DCB) method in order to calculate the bridging stress distribution in polycrystalline aluminas with different grain sizes. In the already existing DCB methods the measured crack opening displacement (COD) in coarse-grained aluminas deviates generally from the calcula-ted one because of the grain-interface bridging in the crack wake. In the current DBC method developed in the present study the effect of the bridging stress was considered in the DCB analysis. whereas the only effect of applied point-loading at the end of DCB specimen was taken into account in the existing DCB analysis The crack closure due to bridging stress was calculated using the power-law relation and the theoretical model developed in Part I of the present paper as bridging stress function and then compared analytically. The limitations of the current DCB methods such as specimen dimensions applied loads and elastic modulus were discussed in detail to provide a reliability of the newly developed DCB analysis for the bridging stress distribu-tion in polycrystalline aluminas.

  • PDF

Effects of a Moving Mass on the Dynamic Behavior of Cantilever Beams with Double Cracks

  • Son, In-Soo;Cho, Jeong-Rae;Yoon, Han-Ik
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.9 no.3
    • /
    • pp.33-39
    • /
    • 2008
  • The effects of a double crack and tip masses on the dynamic behavior of cantilever beams with a moving mass are studied using numerical methods. The cantilever beams are modeled by applying Euler-Bernoulli beam theory. The cracked sections are represented by a local flexibility matrix connecting three undamaged beam segments. The influences of the crack, moving mass, and tip mass, and the coupling of these factors on the vibration mode and the frequencies of the double-cracked cantilever beams are determined analytically. The methodology provides a basis for analyzing the dynamic behavior of a beam with an arbitrary number of cracks and a moving mass.

Development of a double cantilever sandwich beam method for evaluating frequency dependence of dynamic modulus and damping factor of rubber materials (고무의 동탄성계수와 손실계수의 주파수 의존성을 평가하기 위한 양팔 샌드위치보 시험법의 개발)

  • 김광우;최낙삼
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2001.05a
    • /
    • pp.19-22
    • /
    • 2001
  • This paper proposes a double cantilever sandwich-beam method for evaluating the frequency dependence of material dynamic characteristics. The flexural vibration of a double cantilever sandwich-beam specimen with a partially inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Quadratic relationships of dynamic elastic modulus and material loss factor of rubbers with frequency were quantitatively suggested employing the least square error method.

  • PDF

Evaluation of Dynamic Characteristics of Rubber Materials Using a Double Cantilever Sandwich Beam Method (양팔 샌드위치보 시험법에 의한 EPDM고무의 동특성 평가 연구)

  • Kim, Kwang-Woo;Choi, Nak-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.7
    • /
    • pp.1393-1400
    • /
    • 2002
  • A double cantilever sandwich-beam method has been applied to the evaluation of the frequency dependence of dynamic elastic modulus and material loss factor of EPDM rubbers. The flexural vibration of a double cantilever sandwich-beam specimen with an inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Effects of the rubber layer length on the dynamic characteristics were also investigated: reliable values were measured when the length of the inserted rubber layer was larger than and equal to 50% of the effective specimen length. The values were compared with those obtained by the dynamic mechanical analysis and the simple resonant test. Relationships of the dynamic characteristics of rubbers with frequency could be determined using the least square error method.

Experimental damage identification of cantilever beam using double stage extended improved particle swarm optimization

  • Thakurdas Goswami;Partha Bhattacharya
    • Structural Engineering and Mechanics
    • /
    • v.91 no.6
    • /
    • pp.591-606
    • /
    • 2024
  • This article proposes a new methodology for identifying beam damage based on changes in modal parameters using the Double Stage Extended Improved Particle Swarm Optimization (DSEIPSO) technique. A finite element code is first developed in MATLAB to model an ideal beam structure based on classical beam theory. An experimental study is then performed on a laboratory-scale beam, and the modal parameters are extracted. An improved version of the PSO algorithm is employed to update the finite element model based on the experimental measurements, representing the real structure and forming the baseline model for all further damage detection. Subsequently, structural damages are introduced in the experimental beam. The DSEIPSO algorithm is then utilized to optimize the objective function, formulated using the obtained mode shapes and the natural frequencies from the damaged and undamaged beams to identify the exact location and extent of the damage. Experimentally obtained resultsfrom a simple cantilever beam are used to validate the effectiveness of the proposed method. The illustrated results show the effectiveness of the proposed method for structural damage detection in the SHM field.

Influence of Tip Mass and Moving Mass on Dynamic Behavior of Cantilever Pope with Double-crack (이중크랙을 가진 외팔 파이프의 동특성에 미치는 끝단질량과 이동질량의 영향)

  • Son In-Soo;Yoon Han-Ik
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.15 no.4 s.97
    • /
    • pp.483-491
    • /
    • 2005
  • In this paper a dynamic behavior of a double-cracked cantilever pipe with the tip mass and a moving mass is presented. Based on the Euler-Bernoulli beam theory, the equation of motion is derived by using Lagrange's equation. The influences of the moving mass, the tip mass and double cracks have been studied on the dynamic behavior of a cantilever pipe system by numerical method. The cracks section are represented by the local flexibility matrix connecting two undamaged beam segments. Therefore, the cracks are modelled as a rotational spring. This matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory. We investigated about the effect of the two cracks and a tip mass on the dynamic behavior of a cantilever pipe with a moving mass.

A Double Cantilever Sandwich Beam Method far Evaluating Frequency Dependence of Dynamic Modulus and Damping Factor of Rubber Materials (고무의 동탄성계수와 손실계수의 주파수 의존성을 평가하기 위한 양팔 샌드위치보 시험법의 연구)

  • 김광우;박진택;이덕보;최낙삼
    • Composites Research
    • /
    • v.14 no.3
    • /
    • pp.69-76
    • /
    • 2001
  • This paper proposes a double cantilever sandwich-beam method fur evaluating the frequency dependence of dynamic characteristics of rubbers. The flexural vibration of a double cantilever sandwich-beam specimen with an inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Quadratic relationships of dynamic elastic modulus and material loss factor of rubbers with frequency were suggested employing the least square error method.

  • PDF

Analysis of a Composite Double Cantilever Beam with Stitched Reinforcements Under Mixed Mode Loading : Formulation (I)

  • Jang Insik;Sankar Bhavani V.
    • Journal of Mechanical Science and Technology
    • /
    • v.19 no.2
    • /
    • pp.567-577
    • /
    • 2005
  • Several methods for improving the interlaminar strength and fracture toughness of composite materials are developed. Through-the-thickness stitching is considered one of the most common ways to prevent delamination. Stitching significantly increases the Mode I fracture toughness and moderately improves the Mode II fracture toughness. An analytical model has been developed for simulating the behavior of stitched double cantilever beam specimen under various loading conditions. For z-directional load and moment about the y-axis the numerical solutions are compared with the exact solutions. The derived formulation shows good accuracy when the relative error of displacement and rotation between numerical and exact solution were calculated. Thus we can use the present model with confidence in analyzing other problems involving stitched beams.

Impact Behavior at Composite Material of Aluminium Double Cantilever Beam with Two Kinds of Materials (이종재료의 알루미늄 이중 외팔보 복합재의 충격 거동)

  • Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.8 no.3
    • /
    • pp.421-426
    • /
    • 2007
  • This study was analyzed dynamically by finite element method about the results of experiments which the double cantilever beam specimens with two kinds of materials were applied by impact load. And they were compared with each other as the simulation data applied onto impact velocities of 6.4 and 18.47 m/s. The crack energy release rate, force and displacement of block were calculated numerically by computer. As the numerical simulation data of specimen analyzed in this study approached the experimental data, the inspection of this specimen model suggested in this paper could be reasonable for the numerical simulation.

  • PDF