• Title/Summary/Keyword: bending and buckling

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Vibration Analysis of Rotating Cantilever Beams Considering the Elastic Foundation Effect (지지부 탄성효과를 고려한 회전 외팔 보의 진동해석)

  • 윤경재;유홍희
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.1022-1028
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    • 2000
  • This paper presents a modeling method for the vibration analysis of rotating cantilever beams considering the elastic foundation effect. Mass and stiffness matrices are derided explicitly by considering coupling effect between stretching and bonding motion. Numerical results show that the bending direction elastic foundation stiffness influences the vibration characteristics significantly in practical range of beam configuration. The ranges of elastic foundation stiffness to avoid the dynamic buckling are also presented. The method presented in this paper can be used to predict the variations of natural frequencies of rotating cantilever beams with elastically restrained root.

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Critical Loads of Eccentrically Loaded Struts with Thin-Walled Open Sections (편심하중을 받는 박벽개단면 압축재의 임계하중)

  • 나영진;이수곤
    • Computational Structural Engineering
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    • v.9 no.4
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    • pp.135-140
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    • 1996
  • Single angle or channel with thin-walled open section can be used as compression member for example as web member in truss. In this case the inevitable eccentricity due to fabrication is commonly neglected in structural design. However eccentricity effect should be considered in the member design, especially in case of compression member. The critical loads of compression members that buckle by twisting or by a combination of bending and twisting are to be determined by solving governing differential equations. In this paper, the investigations are limited to the rolled channels([), equal-leg angles(L), lipped channels(C) and the applied loads are assumed to have some eccentricities.

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Flexural behaviour of steel plate-masonry composite beams

  • Jing, Deng-Hu;Cao, Shuang-Yin;Shi, Lei
    • Steel and Composite Structures
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    • v.13 no.2
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    • pp.123-137
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    • 2012
  • Steel plate-masonry composite structure is a newly-developed type of structural technique applicable to existing masonry buildings by which the load-bearing walls can be removed for large spaces. This kind of structure has been used in practice for its several advantages, but experimental investigation on its elements is nearly unavailable in existing literature. This paper presents an experimental study on the flexural behaviour of four steel plate-masonry composite beams loaded by four-point bending. Test results indicate that failure of the tested beams always starts from the local buckling of steel plate, and that the tested beams can satisfy the requirement of service limit state. In addition, the assumption of plane section is still remained for steel plate prior to local buckling or steel yielding. By comparative analyses, it was also verified that the working performance of the beam is influenced by the cross-section of steel plate, which can be efficiently enhanced by epoxy adhesive rather than cement mortar or nothing at all. Besides, it was also found that the contribution of the encased masonry to the flexural capacity of the composite beam cannot be ignored when the beam is injected with epoxy adhesive.

Structural Performance Test of Optimized Outer Tie Rod (아우터타이로드 최적화 모델의 구조성능시험)

  • Kim, Jong-Kyu;Seo, Sun-Min;Kim, Young-Jun;Lee, Dong-Jin;Lee, Seul;Park, Young-Chul;Lee, Kwon-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.5
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    • pp.82-87
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    • 2012
  • The outer tie rod that is a part of steering system connects the steering gear to the steering knuckle via the inner tie rod. The formal study suggested the optimized structural design of an outer tie rod installed in a passenger car. Its weight is 284.7g, which is 57.2% lighter weight than initial steel model. This study validates the optimized design of the outer tie rod considering buckling and durability. The assembled unit of an inner tie rod and outer tie rod is utilized to perform the test of the bending strength of the outer tie rod. On the contrary, 1/2 car is utilized to perform the test of its durability performance.

Evaluation of the Load Carrying Capacity of Existing Bridges Using Buckling Equation With Initial Deflection (초기처짐을 갖는 좌굴방정식을 이용한 교량의 내하력 평가)

  • Ki, Wan-Seo;Yang, Seung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.8
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    • pp.2032-2037
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    • 2009
  • The load carrying capacity of bridge structures in public use is generally evaluated without considering their actual behavioral characteristics. This study examined common errors taking place in the evaluation of load carrying capacity of bridge structures. In order to account for their current behavioral characteristics such as the boundary condition, we evaluated the load carrying capacity of a bridge in terms of axial force, which was calculated by applying deflection to the buckling equation for members with initial imperfections, and in terms of bending moment obtained from deflection.

Evaluation of Forming Performance of Cold Rolled Steel Pipes & Tubes for Building Structure (건축구조용 냉간성형 강관의 가공성능 평가)

  • Im, Sung Woo;Choi, Kwang;Chang, In Hwa
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.33-42
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    • 2004
  • Making use of SN steel in the building structure should be a prerequisite to adopt the design strength of said steel. As a preceding study, the material properties of STKN400B/490B tubes and SPAP235/325 and SPAR295 square pipes manufactured using SN400B/490B plates were evaluated. Compared with the yield and ultimate strengths of SN400B/490B plates, those of STKN400B/490B tubes increase. Nonetheless, the yield and ultimate strengths of STKN400B/490B tubes satisfied the design codes of STKN400B/490B tubes even though the tubes were fabricated via roll bending or press forming. On the other hand, the yield and ultimate strengths at the edges of SPAP235/325 square pipes did not satisfy the design codes based on the values at the sides. The maximum tensile and compressive residual stresses at the SN490B tube were equal to and 40% of the yield strength of the SN490B plate, respectively, In the case of the SPAP325 square pipe, both the maximum tensile and compressive residual stresses were 80% of the yield strength of the SN490B plate. The axial compressive loaded column test results snowed that the buckling strengths were not very different regardless of the mode of fabrication of STKN490B tunes. i.e., through roll bending or press forming. On the other hand, the buckling strength of the SPAP325 square pipe was higher than that of the built-up square pipe.

Hygrothermal effects on the vibration and stability of an initially stressed laminated plate

  • Wang, Hai;Chen, Chun-Sheng;Fung, Chin-Ping
    • Structural Engineering and Mechanics
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    • v.56 no.6
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    • pp.1041-1061
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    • 2015
  • The influence of hygrothermal effects on the vibration frequency and buckling load of a shear deformable composite plate with arbitrary initial stresses was investigated. The governing equations of the effects of humid, thermal and initial stresses are established using the variational method. The material properties of the composite plate are affected by both temperature and moisture. The initial stress is taken to be a combination of uniaxial load and pure bending in a hygrothermal environment. The influence of various parameters, such as the fiber volume fraction, temperature, moisture concentration, length/thickness ratios, initial stresses and bending stress ratio on the vibration and stability of the response of a laminated plate are studied in detail. The behavior of vibration and stability are sensitive to temperature, moisture concentration, fiber volume fraction and initial stresses.

Development of On-line Bending Stiffness Tester (2) - Lab experiment - (종이 휨강성 자동 측정방식의 개발과 그 이용 (2) - 실험실 측정 -)

  • Seo, Yung-Bum;Jung, Suk-Myun;Jung, Tae-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.4
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    • pp.21-28
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    • 2007
  • A simple method of on-line stiffness measurement using the wrinkling behavior of paper web between two rollers was presented. The theory and the equation were presented, and lab and mill tests were executed. We called the stiffness measured by Taber tester as 'Taber stiffness', and by tension wrinkling measurement as 'wrinkle stiffness', respectively. Lab experimental results showed Taber and wrinkle stiffness are almost equivalent. In the mill experiment, we could measure the stiffness in the wet state and in the dry state. The dry wrinkle stiffness was close to the taber stiffness, but the wet wrinkle stiffness was much lower than the corresponding taber stiffness.

Flexural Strength of HSB Steel Girders Due to Inelastic Lateral-Torsional Buckling - Sections with Slender Web (HSB 강거더의 비탄성 횡비틂좌굴에 의한 휨강도 - 세장 복부판 단면)

  • Cho, Eun-Young;Shin, Dong-Ku
    • Journal of Korean Society of Steel Construction
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    • v.24 no.2
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    • pp.217-231
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    • 2012
  • The flexural behavior of HSB I-girder with a non-slender web attributed to inelastic lateral-torsional buckling under uniform bending was investigated using nonlinear finite element analysis of ABAQUS. The girder was assumed to have a compact or noncompact web in order to prevent premature bend-buckling of the web. The unbraced length of the girder was selected so that inelastic lateral-torsional buckling governs the ultimate flexural strength. The compression flange was also assumed to be either compact or noncompact to prevent local buckling of the elastic flange. Both homogeneous sections fabricated from HSB600 or HSB800 steel and hybrid sections with HSB800 flanges and SM570-TMC web were considered. In the FE analysis, the flanges and web of I-girder were modeled as thin shell elements. Initial imperfections and residual stresses were imposed on the FE model. An elasto-plastic strain hardening material was assumed for steel. After establishing the validity of the present FE analysis by comparing FE results with test results in existing literature, the effects of initial imperfection and residual stress on the inelastic lateral-torsional buckling behavior were analyzed. Finite element analysis results for 96 sections demonstrated that the current inelastic strength equations for the compression flange in AASHTO LTFD can be applied to predict the inelastic lateral torsional buckling strength of homogeneous and hybrid HSB I-girders with a non-slender web.

Deformation and Fracture Behavior of Wall Thinned Carbon Steel Pipes (감육된 탄소강배관의 변형과 파괴거동)

  • Ahn, Seok-Hwan;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.20 no.4 s.71
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    • pp.17-23
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    • 2006
  • Monotonic four-point bending tests were conducted on straight pipe specimens, 102 mm in diameter with local wall thinning, in order to investigate the effects of the depth, shape, and location of wall thinning on the deformation and failure behavior of pipes. The local wall thinning simulated natural erosion/corrosion metal loss. The deformation and fracture behavior of the straight pipes with local wall thinning was compared with that of non wall-thinning pipes. The failure modes were classifiedas local buckling, ovalization, or crack initiation, depending on the depth, shape, and location of the local wall thinning. Three-dimensional elasto-plastic analyses were carried out using the finite element method. The deformation and failure behavior, simulated by finite element analyses, coincided with the experimental results.