scholarly journals Experimental and Numerical Study on the Lateral-Torsional Buckling of Steel C-Beams with Variable Cross-Section

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 941
Author(s):  
Ida Mascolo ◽  
Mariano Modano ◽  
Antimo Fiorillo ◽  
Marcello Fulgione ◽  
Vittorio Pasquino ◽  
...  
Keyword(s):  
Cross Section ◽  
Numerical Study ◽  
Numerical Approach ◽  
Computational Effort ◽  
Experimental Results ◽  
Variable Cross ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Cross Sectional ◽  
Thin Walled

Metallic thin-walled beams with continuously varying cross-sections loaded in compression are particularly sensitive to instability problems due to lateral-torsional buckling. Such a phenomenon depends on several parameters, including the cross-sectional properties along the entire length, material properties, load distribution, support, and restraint conditions. Due to the difficulty of obtaining analytic solutions for the problem under consideration, the present study takes a numerical approach based on a variational formulation of the lateral-torsional buckling problem of tapered C-beams. Numerical simulations are compared with experimental results on the buckling of a physical model of at thin-walled beam with uniformly varying cross-section, with the aim of assessing the accuracy of the proposed approach. The good agreement between numerical and experimental results and the reduced computational effort highlight that the proposed variational approach is a powerful tool, provided that the geometry of the structure and the boundary conditions are accurately modeled.

Analysis of Singly Symmetric Oval Rings with Variable Cross Section

1970 ◽  
Vol 14 (03) ◽  
pp. 143-152
Author(s):  
J. E. Flaherty ◽  
W. P. Vafakos
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Experimental Results ◽  
Variable Cross ◽  
Cross Sectional ◽  
Shear Loads ◽  
Good Agreement

An analysis of singly symmetric oval rings with variable cross-sectional properties, subjected to arbitrary radial and shear loads, is presented. The flange stresses in nonuniform reinforcing rings of ring-stiffened oval cylinders are obtained by assuming that such cylinders behave as composite rings. The stresses are shown to be in good agreement with available theoretical and experimental results.

Influence of Cross-Section Distortion on the Bending Vibration of Thin-Walled Beams of H Section

1964 ◽  
Vol 6 (3) ◽  
pp. 211-218 ◽  
Author(s):  
A. D. S. Barr ◽  
T. Duthie
Keyword(s):  
Differential Equations ◽  
Cross Section ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Hamilton’S Principle ◽  
Hamilton's Principle ◽  
Bending Vibration ◽  
Cross Sectional ◽  
Thin Walled ◽  
The Cross

Approximate differential equations describing the bending vibration of beams of thin-walled H section, in which the distortion of the cross-section in its own plane is taken into account, are derived from Hamilton's principle using an assumed form for the cross-section deformation. Only the simplest of the cross-sectional deformation configurations which will couple with ordinary bending is considered. The variation with wavelength of the two spectra of frequencies which result from this coupling of the bending and cross-sectional motions is shown for several section geometries. Theoretical curves show reasonable agreement with experimental results from free beams.

Boundary element method in numerical study of three-dimensional Stokes flows in channels of arbitrary shape

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Cross Section ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Periodic Flows ◽  
Element Method

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.

Longitudinal oscillation of a rod with a variable cross section

2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev
Keyword(s):  
Cross Section ◽  
Natural Frequencies ◽  
Liouville Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Independent Functions ◽  
The Cross ◽  
The Right

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.

Experimental performance of optimized trusses

2021 ◽  
Author(s):  
Joshua A. Schultz ◽  
Phillip Geist ◽  
Brooke Whitsell ◽  
Rachel Dorr
Keyword(s):  
Point Load ◽  
Experimental Results ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Experimental Performance ◽  
High Rise ◽  
Truss Topology ◽  
Failure Loads ◽  
3D Printed

<p>A series of six 3D printed discretely optimized truss specimens and two warren truss specimens were experimentally loaded until failure. The results were compared to the theoretical failure loads and stresses determined using Maxwell’s Method. Each set of truss specimens were loaded in a simple span condition, with a point load applied at the center of the span. Each truss specimen was configured into pairs in order to prevent lateral torsional buckling (LTB) while testing. Strain, load, and displacement data was gathered for each truss specimen tested. These results were compared to the predicted results calculated by Maxwell’s theorem. Of the 6 specimens tested, all of the trusses failed within 1% - 20% of the analytical vales. The trends in the experimental results support efficacy of previously developed theories of optimized truss topology in order to increase strength and efficiency of lateral systems in high rise structures.</p>

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