• 제목/요약/키워드: beam transformation

검색결과 207건 처리시간 0.021초

Wavelet Transform을 이용한 충격력을 받는 회전하는 외팔 보의 진동 특성 해석 (Vibration Analysis of a Rotating Cantilever Beam Undergoing Impulsive Force Using Wavelet Transform)

  • 박호영;유홍희
    • 한국소음진동공학회논문집
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    • 제18권10호
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    • pp.1024-1032
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    • 2008
  • The vibration characteristics of a rotating cantilever beam undergoing impulsive force are investigated using wavelet transformation. The transient response induced by the impulsive force and the rigid body motion of the beam are calculated using hybrid deformation variable modeling along with the Rayleigh-Ritz assumed mode methods. The vibration characteristics of the beam can be analyzed in time-frequency domain with the wavelet transform method. Therefore, the effects of the impulsive force on the transient vibration characteristics of the beam can be investigated more effectively.

Wavelet Transform을 이용한 충격력을 받는 회전하는 외팔 보의 진동 특성 해석 (Vibration Analysis of a Rotating Cantilever Beam Undergoing Impulsive Force Using Wavelet Transform)

  • 박호영;유홍희
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 춘계학술대회논문집
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    • pp.400-406
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    • 2008
  • The vibration characteristics of a rotating cantilever beam undergoing impulsive force are investigated using wavelet transformation. The transient response induced by the impulsive force and the rigid body motion of the beam are calculated using hybrid deformation variable modeling along with the Rayleigh-Ritz assumed mode methods. The vibration characteristics of the beam can be analyzed in time-frequency domain with the wavelet transform method. Therefore, the effects of the impulsive force on the transient vibration characteristics of the beam can be investigated more effectively.

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현장계측에 의한 쏘일네일링 보강벽체의 변형특성에 관한 고찰 (A Consideration on Deformation Characteristics of Soil Nailed Retaining-Walls on Field Measurements)

  • 윤배식;이종문;강인규;권영호;김홍택
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.534-537
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    • 2007
  • The soil nailing was generally using method in practical business, in application of the soil nailing, the analysis was primarily used to Beam-Colum Method, Finite Element Method and Limit Equilibrium Method. Beam-Colum Method and Finite Element Method were able to examine transformation but widely using Limit Equilibrium Method wasn't able to examine transformation and displacement Therefore, this study was focused on presenting stability in comparison with former study-results about horizontal displacement of the soil nailing retaining-walls satisfing a criterion safety factor of Limit Equilibrium. There were performing comparison field measurements and former study-results in first step.

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Nonlinear Aeroelastic Analysis of a High-Aspect-Ratio Wing with Large Deflection Effects

  • Kim, Kyung-Seok;Lim, In-Gyu;Lee , In;Yoo, Jae-Han
    • International Journal of Aeronautical and Space Sciences
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    • 제7권1호
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    • pp.99-105
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    • 2006
  • In this study, nonlinear static and dynamic aeroelastic analyses for a high-aspect-ratio wing have been performed. To achieve these aims, the transonic small disturbance (TSD) theory for the aerodynamic analysis and the large deflection beam theory considering a geometrical nonlinearity for the structural analysis are applied, respectively. For the coupling between fluid and structure, the transformation of a displacement from the structural mesh to the aerodynamic grid is performed by a shape function which is used for the finite element and the inverse transformation of force by work equivalent load method. To validate the current method, the present analysis results of a high-aspect-ratio wing are compared with the experimental results. Static deformations in the vertical and torsional directions caused by an angle of attack and gravity loading are compared with experimental results. Also, static and dynamic aeroelastic characteristics are investigated. The comparisons of the flutter speed and frequency between a linear and nonlinear analysis are presented.

웨이블렛 변환 기법을 이용한 선체 구조의 결함진단 (Damage Detection of Ship Structures Using Wavelet Transformation)

  • 이대성;조대승
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.815-820
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    • 2000
  • The early damage detection of large structures is very important to prevent the disaster due to its global failure. In this paper, a damage detection method of the beam-analogy structure based on the wavelet transformation of mode shape is presented. This can effectively detect the singularity of mode shape caused to the inconsistency of bending moment and shear force at the damaged part using the discrete wavelet and its inverse transforms. To investigate the validity and the applicability of the presented damage detection method, numerical simulation and experiment are carried out for the idealized beam and the real ship structures.

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고온용 NITINOL 형상기억합금의 열적/기계적 특성 평가 (Thermo-mechanical Characteristics of High Temperature NITINOL Shape Memory Alloy)

  • 윤성호
    • 한국정밀공학회지
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    • 제19권10호
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    • pp.52-59
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    • 2002
  • The thermo-mechanical characteristics of high temperature NITINOL shape memory alloy were evaluated using DSC with small samples and DMA with three-point bending specimens. The shape memory alloy of 54.4Ni/45.5Ti wt.% was used so that the phase transformation temperatures were in the range of 50~11$0^{\circ}C$. Two types of sample were tested in the experiments corresponding to as-received and annealed conditions. Simple beam bending theory was used to calculate the dynamic moduli of the shape memory alloy. According to the results, a large discrepancy in transformation temperatures was found between DSC and DMA techniques. Annealing treatment was found to suppress the R-phase transformation during cooling and the secondary plateau in the austenite transformation. Such a heat treatment was also significantly influenced to raise the transformation temperatures and the moduli of the shape memory alloy.

미분변환에 의한 비균질 보의 진동해석 (Natural Frequencies for Inhomogeneous Beams by Differential Transformation)

  • Mun, Kwon-Kyung;Jae, Shin-Yung;Ryu, Yung-Soon
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.617-621
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    • 2001
  • 본 연구는 비균질 보의 진동해석에 새로운 선형 및 비선형 비분방정식의 해석인 미분변환방법을 적용하였으며, 미끄럼지지와 고정지지 및 미끄럼지지와 핀 지지의 경계조건을 고려하여 비균질 보에 대한 수치해석을 수행하였다. 본 해석법의 타당성을 검증하기 위하여 기존의 연구결과와 비교 검토하였으며, 그 결과 본 연구에 의한 해석결과가 기존의 것과 잘 일치함을 알 수 있었다.

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Procedures for determination of elastic curve of simply and multiple supported beams

  • Biro, Istvan;Cveticanin, Livija
    • Structural Engineering and Mechanics
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    • 제60권1호
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    • pp.21-30
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    • 2016
  • In this paper two procedures for determination of the elastic curve of the simply and multiple supported beams are developed. Determination of the elastic curve is complex as it requires to solve a strong nonlinear differential equation with given boundary conditions. For numerical solution the initial guess of the slope at the end of the beam is necessary. Two procedures for obtaining of the initial guess are developed: one, based on transformation of the supported beam into a clamped-free one, and second, on the linearization of the problem. Procedures are applied for calculating of elastic curve of a simply supported beam and a beam with three supports. Obtained results are compared. Advantages and disadvantages of both methods are discussed. It is proved that both suggested procedures give us technically accurate results.

CTBA Tubular Beam의 열간 성형해석 및 실험 (Hot Stamping Simulations and Experiments for CTBA Tubular Beams)

  • 서창희;김우성;성지현;박종규;김용식;김영석
    • 소성∙가공
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    • 제24권1호
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    • pp.13-19
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    • 2015
  • For an accurate analysis of hot stamping, a coupled simulation with different aspects of the process(i.e. mechanical, thermal, and phase transformation) is needed. However, coupled simulations are time consuming and costly. Therefore, the current study proposes a simplified method focused on the forming for the hot stamping simulation of a coupled torsion beam axle (CTBA) tubular beam. In this simplified method, non-isothermal conditions were assumed and only conduction was considered, since it represents the majority of the heat transfer during hot stamping. In addition, temperature and strain rate effects were also included. Moreover, an isothermal simulation was conducted and compared with a non-isothermal simulation. Finally, the simulations were verified by experiments. In conclusion, the proposed method is shown to be effective for the development of tube-type parts, and it effectively predicts the deformation of the tubular beam during hot stamping.

무소음무진동 보보강공법 개발에 관한 연구(2) (Development of Retrofit Method for Beam Using Steel Plate Reinforced by Fiber Sheet (2))

  • 김우재;최종문
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.503-506
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    • 2005
  • The purpose of this study was the Development of Retrofit Method for Beam Using Steel Plate Reinforced by Fiber Sheet.1. Additional reinforcements are not needed in the joining area of slab and beam web.2. Beam using carbon fiber reinforced plastic displays low effects in shearing effect.3. Beams reinforced steel plate by epoxy effect the capacities of strength. But the capacities of strength are rapidly reduced when adhesive surface be omitted. Thus details are needed in this case.4.Retrofit method for beam using steel plate reinforced by fiber sheet with epoxy rosin improves the capacities of strength and the initial stiffness, shows a large transformation since the maximum load likewise may be excellent to the shearing reinforcement.

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