Geometric imperfections such as radial imperfection, diamond shape, and local dimples could affect the buckling mode and load carrying capacity of axially compressed steel tubular columns. This paper experimentally investigates the effect of radial imperfection on the load carrying capacity of tubular columns. Test samples include 100 specimens with different values for diameter, length, thickn...

Searches of the electric dipole moment (EDM) at a pure magnetic ring, like COSY, encounter strong background coming from magnetic dipole moment (MDM). The most troubling issue is the MDM spin rotation in the so-called imperfection, radial and longitudinal, B-fields. To study the systematic effects of the imperfection fields at COSY we proposed the original method which makes use of the two stat...

in this paper, the finite element analysis of stability problem of vehicle composite drive shafts subjected to torsional loading is studied. first, using the minimum total potential energy principle, the governing equations are derived and then they are solved by finite element method. the initial geometrical imperfection which is usually in the form of radial displacement, is taken into consid...

We present results from an experimental and numerical investigation on the compression, and consequent buckling, of a slender rod constrained inside a horizontal cylinder. An experimental model system is developed to systematically study the sequence of instabilities from straight-to-sinusoidal and sinusoidal-to-helical configurations. We quantify the associated buckling loads as a function of ...

Thin walled cylindrical shells are important components of industrial structures such as liquid storage tanks, silos, etc. Shell buckling is usually a major failure mode of thin walled shells under extreme loads such as earthquakes. Longitudinal and radial stiffeners are generally used in order to increase buckling capacity of thin walled shells. During an earthquake, cylindrical shells may exp...

One of the common failure modes of thin cylindrical shell subjected external pressure is buckling. The buckling pressure of these shell structures are dominantly affected by the geometrical imperfections present in the cylindrical shell which are very difficult to alleviate during manufacturing process. In this work, only three types of geometrical imperfection patterns are considered namely (a...

Perfect graphs constitute a well-studied graph class with a rich structure, reflected by many characterizations with respect to different concepts. Perfect graphs are, for instance, precisely those graphs G where the stable set polytope STAB(G) coincides with the fractional stable set polytope QSTAB(G). For all imperfect graphs G it holds that STAB(G) ⊂ QSTAB(G). It is, therefore, natural to us...