Advances in dynamic instability: can a beam-column undergo tensile flutter?

Tensile instability in beam-like structures has been highlighted in very few papers; the studies reported in the specific literature are limited to beam-columns characterised either by high shear deformation or by the presence of a single structural junction allowing a transversal displacement discontinuity. Moreover, to the authors’ knowledge, the flutter instability associated to tensile axial load has not yet been disclosed. This work aims to offer further contribution to the knowledge of tensile instability of beam-columns by considering the dynamic instability of an Euler Bernoulli beam in presence of an arbitrary number of internal sliders endowed with translational elastic springs. The use of the generalised functions allows an exact evaluation of the eigensolution, provided in closed form, both for conservative and nonconservative axial load. In particular, the following relevant question is posed: Can a beam-column undergo tensile flutter instability? A comprehensive parametric analysis conducted in this work gives an affirmative answer to the asked question.

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Stability of imperfect prestressed stayed beam-columns under combined axial load and bending

Engineering Structures ◽

10.1016/j.engstruct.2021.112891 ◽

2021 ◽

Vol 245 ◽

pp. 112891

Author(s):

Kaidong Wu ◽

Zhe Xing

Keyword(s):

Axial Load ◽

Beam Columns

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Stable Limit Axial Load Ratios of Concrete Filled Steel Tubular Beam-Columns Under Varying Axial Loads

Lecture Notes in Civil Engineering - EASEC16 ◽

10.1007/978-981-15-8079-6_157 ◽

2020 ◽

pp. 1701-1712

Author(s):

L. Li

Keyword(s):

Axial Load ◽

Stable Limit ◽

Axial Loads ◽

Beam Columns

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Transverse Vibration of a Viscoelastic Column With Initial Curvature Under Periodic Axial Load

Journal of Applied Mechanics ◽

10.1115/1.3564776 ◽

1969 ◽

Vol 36 (4) ◽

pp. 814-818 ◽

Cited By ~ 15

Author(s):

K. K. Stevens

Keyword(s):

Polymethyl Methacrylate ◽

Transverse Vibration ◽

Axial Load ◽

Dynamic Instability ◽

Complex Modulus ◽

Lateral Vibrations ◽

Lateral Response ◽

Viscoelastic Column ◽

Linear Viscoelastic ◽

Frequency Curves

The lateral response of a slightly curved viscoelastic column subjected to a periodic axial load P0 + P1 cos ωt is investigated. The analysis makes use of the complex modulus representation for linear viscoelastic materials. It is shown that the lateral vibrations stemming from imperfections can be of significant amplitude. Experimentally determined amplitude-frequency curves for a polymethyl methacrylate (Plexiglas) column are presented, and are found to be in excellent agreement with the theory. It is shown that there is an analogy between the dynamic instability and the static buckling of imperfect columns.

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STRUCTURAL PERFORMANCE OF DAMAGED OPEN-WEB TYPE SRC BEAM-COLUMNS WITH BOLT-CONNECTED BATTEN STEEL PLATES AFTER RETROFITTING

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2015.112 ◽

2015 ◽

Vol 2 (1) ◽

Author(s):

Takahiro Kume ◽

Takashi Fujinaga ◽

Yuping Sun

Keyword(s):

Axial Load ◽

Steel Plates ◽

Analytical Models ◽

Structural Performance ◽

Test Results ◽

Beam Columns ◽

Cyclic Lateral Load ◽

Load Carrying ◽

Lower Load ◽

Constant Axial Load

In this paper, structural performance of damaged SRC beam-columns with open-web type of batten steel plate after retrofitting was investigated. Three open-web type SRC beam-columns with bolt-connected batten steel plates were fabricated and tested under combined constant axial load and cyclic lateral load. At first, each beam-column was　cyclically loaded to the targeted displacement. After the first loading, the test columns were retrofitted and reloaded till large deformation or failure. The damaged portion of each column was retrofitted with the polymer cement mortar and epoxy resin was injected into the cracks. The measured stiffness of retrofitted columns varied between 71.4% and 85.5% of the initial one. And, test results also indicated that the column which experienced the larger displacement and higher axial load showed lower load carrying capacity, but the others showed approximately the same capacities as the initial columns. Numerical analysis was also conducted to explain the retrofitted columns. Analytical results predicted the experimental behavior fairly well, which verifies the validity of the analytical models in low axial load.

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ULTIMATE STRENGTH OF CONCRETE FILLED SQUARE STEEL TUBULAR BEAM-COLUMNS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2017.174 ◽

2017 ◽

Vol 4 (1) ◽

Author(s):

Masayuki Haraguchi ◽

Masae Kido ◽

Keigo Tsuda

Keyword(s):

Ultimate Strength ◽

Axial Load ◽

Shooting Method ◽

Slenderness Ratio ◽

Limit State ◽

Load Ratio ◽

Maximum Strength ◽

Rotational Angle ◽

Beam Columns ◽

Axial Load Ratio

The objective of this study is to examine the ultimate strength of CFT columns. The range of the axial load ratio and the slenderness ratio in which CFT beam-columns reach the full plastic moment are examined on the basis of the strength formulas specified by AIJ Recommendation for Limit State Design of Steel Structures. The CFT columns are subjected to the constant axial compressive force and the monotonic moment at the one end, as the analytical parameters the axial load ratio and slenderness ratio are selected. The analysis is carried out by the shooting method. Bending moment-rotational angle relationships are calculated by the shooting method and the maximum strengths of CFT columns are obtained. When the value obtained by multiplying the axial load ratio and the second power of the slenderness ratio is 0.05, the maximum strength reach 95% of the full plastic moment under the condition that the axial load ratio value is less than or equal to 0.75. When the value obtained by multiplying the axial load ratio and the second power of the slenderness ratio is 0.1, the maximum strength reach 95% of the full plastic moment under the condition that the axial load ratio value is less than or equal to 0.5.

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Prediction of axial hysteresis in locked coil ropes

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247v315341 ◽

1996 ◽

Vol 31 (5) ◽

pp. 341-351 ◽

Cited By ~ 3

Author(s):

M Raoof ◽

I Kraincanic

Keyword(s):

Theoretical Model ◽

Cross Section ◽

Axial Load ◽

Dynamic Instability ◽

Contact Forces ◽

Damping Capacity ◽

Outermost Layer ◽

Parametric Studies ◽

Load Perturbations ◽

Practical Implications

In published literature, the strand constructions dealt with have almost invariably involved only wires which are circular in cross-section. There are, however, instances when shaped wires are used in, for example, half-lock and full-lock coil constructions. The paper reports details of a theoretical model which enables an insight to be gained into various characteristics of axially loaded lock coil ropes. The model is based on an extension of a previously reported orthotropic sheet concept and provides a fairly simple means of estimating wire kinematics, interwire/interlayer contact forces, effective axial stiffnesses and axial hysteresis in axially preloaded locked coil ropes experiencing uniform cyclic axial load perturbations. The theory takes interwire contact deformations and friction into account. Final numerical results based on theoretical parametric studies on some substantial cables highlight the substantial role that the outermost layer(s) with shaped wires play as regards the overall axial damping capacity of fully bedded-in (old) locked coil ropes, and it is found that (for the same lay angles and outer diameters) axial hysteresis in locked coil ropes is generally higher than spiral strands which are composed of only round wires. This finding may have significant practical implications in terms of the design against dynamic instability of structures supported by such cables.

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