The performance of the finite element method (FEM) may be improved in three ways. The first is by the h-version to refine the finite element mesh and the second is by the p-version to increase the order of polynomial shape functions for a fixed mesh. The third is simultaneously to refine the mesh and increase the degrees of elements uniformly or selectively, called the h-p version, which is a c...

It is well known that optimisation of structures where instability phenomena are present can result in severe imperfection sensitivity [9, 10]. Classical examples are the simple Augusti model and stiffened plates [2, 4]. In both examples, the imperfection sensitivity is due to the interaction of two buckling modes. If the critical loads corresponding to the two buckling modes are well separated...

Abstract: Consistent Imperfection Mode Method (CIMM) is a widely-used and effective numerical method to study the buckling capacity of spatial structure. CIMM used an “artificial” deformation instead of “artificial” load eccentricity to imitate the initial disturbance/imperfection for calculation of buckling load, and the basic mode obtained from linear buckling analysis could be used to simula...

As the most rigid cytoskeletal filaments, microtubules bear compressive forces in living cells, balancing the tensile forces within the cytoskeleton to maintain the cell shape. It is often observed that, in living cells, microtubules under compression severely buckle into short wavelengths. By contrast, when compressed, isolated microtubules in vitro buckle into single long-wavelength arcs. The...

In films, mats, buckypaper, and other materials composed of carbon nanotubes (CNTs), individual CNTs are bound together by van der Waals forces and form entangled networks of bundles. Mesoscopic dynamic simulations reproduce the spontaneous self-assembly of CNTs into continuous networks of bundles and reveal that the bending buckling and the length of CNTs are the two main factors responsible f...

Analytical buckling models are important for down-hole operations to ensure the structural integrity of the drill string. A literature survey shows that most published analytical buckling models do not address the effects of inclination angle, boundary conditions or friction. The objective of this paper is to study the effects of boundary conditions, friction and angular inclination on the heli...