• Title/Summary/Keyword: Stiffener

Search Result 434, Processing Time 0.033 seconds

Vibration Analysis of Stiffened Opening Thick Plate (유공 보강 후판의 진동해석)

  • 이효진;김일중;오숙경;정진택;이용수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.05a
    • /
    • pp.794-798
    • /
    • 2004
  • This paper is analysis of stiffened opening thick plate on foundation. This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. In this paper, vibration analysis of rectangular opening thick plate is done by use of Serendipity finite element with 8 nodes by considering shearing strain of plate. And vibration analysis of stiffener is done by used of Timoshenko beam-column element wit 3 nodes. It is shown that natural frequencies depend on not only Winkler foundation parameter but also shear foundation parameter, opening position, opening size, stiffener size.

  • PDF

A Study on the Structural Modification of the Open Box Type Structure by Using the Stiffener (보강재를 이용한 열린 상자형 구조물의 구조변경법에 관한 연구)

  • 박석주;최창우;오창근;왕지석;정재현
    • Journal of KSNVE
    • /
    • v.6 no.1
    • /
    • pp.57-64
    • /
    • 1996
  • The objectiv of this paper is to offer the method of the optimum structural modification by fixing the stiffener on the structure. The vibrational characteristics of a open box type structure are analyzed by the sub-structure synthesis method and sensitivies of each sub-structure are calculated by sensitivity analysis method. The positions to modify are found and the quantities to change are obtained by optimization techniques. As the result, it was found that; (1) The sensitivites of the natural frequency could easily be calculated by the sensitivity analysis method and the optimum position to fix stiffeners could be found. (2) The exact size of stiffeners could be calculated by the optimum structural modification method and the natural frequency could be easily shifted to the objective value. (3) It could be confirmed that the stiffener is a effective tool for accomplishing structural modification.

  • PDF

Strength Evaluation Formulae for Ring-stiffened Tubular T-joints (환보강 T형 관이음부의 강도산정식)

  • 조현만;류연선
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2002.10a
    • /
    • pp.533-540
    • /
    • 2002
  • Tubular joints having a large diameter are reinforced using internal ring stiffener in order to increase the load carrying capacity. In this study, the static strengths of Internally ring-stiffened tubular T-joints subjected to compressive brace loading are assessed. Nonlinear finite element analyses are used to compute the behavior of unstiffened and ring-stiffened T-joints. From the numerical results, Internal ring stiffener is found to efficient in improving the ultimate capacity, and reinforcement effect are calculated. The influence of geometric parameters for members and ring is evaluated. Based on the FE results, regression analysis is performed considering practical sizes of ring stiffener, finally strength estimation formulae for ring-stiffened T-joints are proposed.

  • PDF

Strength Prediction and Optimum Design of Internally Ring-Stiffened Tubular X-and T-Joints (내부 환보강 X형 및 T형 관이음부의 강도산정과 최적설계)

  • Cho, Hyun-Man;Ryu, Yeon-Sun;Lee, Hyun-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2007.04a
    • /
    • pp.315-320
    • /
    • 2007
  • An effective reinforcement method for steel tubular joints having a large chord diameter is the use of internal ring stiffeners. This paper presents the results of a numerical study on the static strength of internally ring-stiffened tubular X- and T-joints subjected to brace axial compression loading. Nonlinear finite element analyses are used to compute the joint strength. The influence of geometrical parameters has been studied and the maximum reinforcement effect of a ring stiffener has been evaluated. A strength ratio is defined. by the ratio of ring-stiffened joint strength to unstiffened joint strength, and an equation for this strength ratio is derived by regression analysis. Design optimization for ring stiffener of tubular joints is carried out using metropolis genetic algorithm.

  • PDF

Analysis of Dynamics Characteristics and Design of vibrating Table for Expendable Pattern Casting Process (소실모형주조용 진동장치의 동특성 분석 및 설계)

  • 이은경;설진수;임경화;이경환
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.05a
    • /
    • pp.269-274
    • /
    • 2003
  • Vibration table is required to obtain high packing density in expendable pattern casting process. Packing density, which is an important manufacture factor, depends on the vibration pattern induced by vibration table. Modal test is utilized to identify the dynamic characteristics of vibration table. And finite element method is used to modify flask by fixing the stiffener. The positions of stiffener to modify are found and the natural frequency could be easily shifted to the objective value by using sensitivity analysis.

  • PDF

The Buckling Analysis of Stiffened Plate with Hole($1^{st}$ Report) -Compression Buckling- (보강(補剛)된 유공판(有孔板)의 좌굴강도해석(挫屈强度解析)(제1보)(第1報) -압축(壓縮) 좌굴(挫屈)-)

  • S.J.,Yim;C.D.,Jang;S.S.,Na
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.19 no.4
    • /
    • pp.11-18
    • /
    • 1982
  • When the perforated plate is under in-plane load of compression, buckling analysis becomes to be necessary because of the presence of stress concentration around holes. To constraint it, we need reinforcement. The methods of reinforcement are attaching doubler around hole and attaching stiffener in the direction of initial stress. In this paper, two methods are investigated mentioned above, which of the two better effective reinforcement. In the consequence of the above investigation, following conclusion was obtained. The method of doubler reinforcement was less buckling stress than that of stiffener because the former had large compressive stress. So, effective method of reinforcement is stiffener reinforcement.

  • PDF

A Study on Application of High-Strength Vertical Stiffeners to Plate Girder (판형교에 고강도 수직보강재 적용에 관한 연구)

  • Chang, Kyong-Ho;Kang, Jae-Hoon;Jang, Gab-Chul
    • Journal of Korean Association for Spatial Structures
    • /
    • v.4 no.4 s.14
    • /
    • pp.137-144
    • /
    • 2004
  • Recently, as steel structures become higher and more long-spanned, application of high-strength steels is increasing gradually. However, criteria and example for design of high-strength steel are not built up. exiting criteria for structural steels is not proper for economical design of high-strength steel. Moreover, exiting criteria will be decrease the fatigue performance of steel bridge using high-strength steel. Therefore, criterion for application of high-strength steel must be established. In this paper, the behavior of plate girder using high-strength vertical stiffeners was clarified by carrying out layer elastic-plastic finite element analysis using finite deformation theory. In order to optimize the design and construction of plate girder using high-strength vertical stiffener, criterion for application of high-strength vertical stiffener is proposed.

  • PDF

Static Strength of Internally Ring-Stiffened Tubular T-Joints (내부 환보강 T형 관이음부의 정적강도)

  • CHO HYUN-MAN;RYU YEON-SUN
    • Journal of Ocean Engineering and Technology
    • /
    • v.18 no.6 s.61
    • /
    • pp.70-78
    • /
    • 2004
  • In order to increase the load carrying capacity of tubular structures, the joints of tubular members are usually reinforced with various reinforcement system. A stiffening method with internal ring stiffeners is effectively used for the steel tubular joint with a large diameter. In this study, the behavior of internally ring-stiffened tubular T-joints subjected to axial loading is assessed. For the parametric study, nonlinear finite element analyses are used to compute the static strength on non-stiffened and ring-stiffened T-joints. Based on the numerical results, an internal ring stiffener is found to be efficient in improving the static strength. The influence of geometric parameters has been determined, and the reinforcement effect are evaluated. Based on the FE results, regression analises are performed considering the practical size of ring stiffener. Finally strength estimation formulas for ring-stiffened tubular T-joints are proposed.

Experimental and analytical study of steel slit shear wall

  • Khatamirad, Milad;Shariatmadar, Hashem
    • Steel and Composite Structures
    • /
    • v.24 no.6
    • /
    • pp.741-751
    • /
    • 2017
  • A steel slit shear wall has vertical slits and when it is under lateral loads, the section between these slits has double-curvature deformation, and by forming a flexural plastic hinge at the end of the slit, it dissipates the energy on the structure. In this article, Experimental, numerical and analytical analyses are performed to study the effect of slit shape and edge stiffener on the behavior of steel slit shear wall. Seismic behavior of three models with different slit shapes and two models with different edge stiffener shapes are studied and compared. Hysteresis curves, energy dissipation, out of plane buckling, initial stiffness and strength are discussed and studied. The proposed slit shape reduces the initial stiffness, increases the strength and energy dissipation. Also, edge stiffener shape increases the initial stiffness significantly.

Torsional response of stiffened circular composite spar (보강된 복합재 원형 스파의 비틀림 거동)

  • Kim, Sung Joon;Lee, Donggeon
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.27 no.1
    • /
    • pp.51-56
    • /
    • 2019
  • To reduce the structural weight, thin-walled circular composite tube has been used as a main spar of high altitude-long endurance unmanned air vehicle(HALE UAV). Predicting the torsional response of stiffened circular spar is complex due to the inhomogeneous nature of section properties, which are dependent on fiber architecture and constituent material properties. The stiffener were placed in the top and bottom sectors of a tube to increase the torsional capabilities such as the rigidity and buckling strength. Numerical simulations were performed to estimate the effect of the stiffener on the torsional capacities. A static experimental test was performed on a stiffened tube, and the test results were compared with a numerical model. The numerical models showed good correlation and demonstrated the ability to predict the torsional capacity. Results presented herein will exhibit the effectiveness of stiffener on torsional strength and stiffness.