Observations on the thermally induced twist of thin-walled open-section booms

1971 ◽  
Vol 8 (5) ◽  
pp. 534-536 ◽  
Author(s):  
SHABEER AHMED
Keyword(s):  
Thermally Induced ◽  
Open Section ◽  
Thin Walled

Pretwisted Curved Beams of Thin-Walled Open Section

1972 ◽  
Vol 39 (3) ◽  
pp. 779-785 ◽  
Author(s):  
A. I. Soler
Keyword(s):  
Numerical Technique ◽  
Equations Of Motion ◽  
Highway Bridges ◽  
Major Effect ◽  
Curved Beams ◽  
Open Section ◽  
Straight Beam ◽  
Thin Walled ◽  
Bending Modes ◽  
Axes Of Symmetry

Equations of motion are derived for coupled extension, flexure, and torsion of pretwisted curved bars of thin-walled, open section. The derivation is based on energy principles and includes inertia terms. The major effect of initial pretwist is to allow coupling of all possible beam deformation modes; however, if the bar is straight and has two axes of symmetry, pretwist causes coupling only between the two bending modes, and between extension and torsion. The governing equations are presented in first-order form, and a numerical technique is suggested for the case of space varying pretwist. It is suggested that these equations may form the basis for a simplified study of the effect of superelevation on the static and dynamic response of curved highway bridges. Finally, a simple straight beam with uniform pretwist is studied to compare effects of pretwist and restrained torsion in a thin-walled beam of open section.

scholarly journals Numerical analysis of stability of an axially-compressed i-beam rod subjected to constrained torsion

2020 ◽  
pp. 11-27
Author(s):  
Amirshokh Kh. Abdurakhmonov
Keyword(s):  
Numerical Analysis ◽  
Axial Force ◽  
Analytical Data ◽  
Practical Interest ◽  
Numerical Calculations ◽  
Analysis Method ◽  
Numerical Analysis Method ◽  
Open Section ◽  
Thin Walled ◽  
Analysis Of Stability

Introduction. Today thin-walled structures are widely used in the construction industry. The analysis of their rigidity, strength and stability is a relevant task which is of particular practical interest. The article addresses a method for the numerical analysis of stability of an axially-compressed i-beam rod subjected to the axial force and the bimoment. An axially compressed i-beam rod is the subject of the study. Materials and methods. Femap with NX Nastran were chosen as the analysis toolkit. Axially compressed cantilever steel rods having i-beam profiles and different flexibility values were analyzed under the action of the bimoment. The steel class is C245. Analytical data were applied within the framework of the Euler method and the standard method of analysis pursuant to Construction Regulations 16.13330 to determine the numerical analysis method. Results. The results of numerical calculations are presented in geometrically and physically nonlinear settings. The results of numerical calculations of thin-walled open-section rods, exposed to the axial force and the bimoment, are compared with the results of analytical calculations. Conclusions. Given the results of numerical calculations, obtained in geometrically and physically nonlinear settings, recommendations for the choice of a variable density FEM model are provided. The convergence of results is estimated for different diagrams describing the steel behavior. The bearing capacity of compressed cantilever rods, exposed to the bimoment, is estimated for the studied flexibility values beyond the elastic limit. A simplified diagram, describing the steel behaviour pursuant to Construction regulations 16.13330, governing the design of steel structures, is recommended to ensure the due regard for the elastoplastic behaviour of steel. The numerical analysis method, developed for axially-compressed rods, is to be applied to axially-compressed thin-walled open-section rods. National Research Moscow State University is planning to conduct a series of experiments to test the behaviour of axially-compressed i-beams exposed to the bimoment and the axial force. Cantilever i-beams 10B1 will be used in experimental testing.

On distortion of symmetric and periodic open-section thin-walled members

2015 ◽  
Vol 94 ◽  
pp. 314-324 ◽  
Author(s):  
Rodrigo Gonçalves ◽  
Dinar Camotim
Keyword(s):  
Open Section ◽  
Thin Walled

Measurements of Torsional Stiffness Changes and Instability Due to Tension, Compression, and Bending

1953 ◽  
Vol 20 (4) ◽  
pp. 553-560
Author(s):  
H. L. Engel ◽  
J. N. Goodier
Keyword(s):  
Nonlinear Behavior ◽  
Torsional Stiffness ◽  
Open Section ◽  
Thin Walled

Abstract The measurements reported verify theoretically predicted effects of tension, compression, and bending, on the torsional stiffness of uniform bars of thin-walled open section. Related modes of buckling and types of nonlinear behavior in torsion are indicated analytically and exhibited in tests, some of these being apparently new.

Torsional and Flexural Buckling of Bars of Thin-Walled Open Section Under Compressive and Bending Loads

1942 ◽  
Vol 9 (3) ◽  
pp. A103-A107 ◽  
Author(s):  
J. N. Goodier
Keyword(s):  
Lateral Buckling ◽  
Flexural Buckling ◽  
Open Section ◽  
Bending Loads ◽  
Thin Walled ◽  
General Section ◽  
Observed Behavior

Abstract The observed behavior of torsionally weak columns in buckling by twisting rather than, or as well as, bending is analyzed in this paper on the basis of a hypothesis due to Wagner. The theory is simplified, and extended to the general section, where results simpler than some already obtained by Kappus are given. It is further extended to bars, restrained by flexible sheets, and bars with constrained axes of rotation. Wagner’s hypothesis is applied to the problem of lateral buckling, where it yields the accepted theory for symmetrical sections, but indicates results of novel form for unsymmetrical cases. Similar results are obtained in the problem of eccentric thrust, whatever the section.

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