A continuum topology optimization methodology suitable for finding optimal forms of large-scale sparse structures is presented. Since the need to avoid long compressive spans can be critical in determining the optimal form of such structures, a formulation is used wherein the structure is modeled as a linear elastic continuum subjected to design loads, and optimized in form to maximize the mini...

Steady progress in the miniaturization of structures and devices has reached a scale where thermal fluctuations become relevant it is thus important to understand how such affect their mechanical stability. Here, we investigate buckling thermalized sheets demonstrate that increase critical load due enhanced scale-dependent bending rigidity for are much larger than characteristic length scale. T...

The accurate value of thermal expansion coefficient ( ) of thin film is an important thermal property in the design of microelectronic devices and microsystem. This research presents a microbridge buckling deformation caused by the residual stresses to determine the of thermal oxide (SiO2) film. The extraction of is supported through experimental means and finite element analysis (FEM) of the b...

Direct near field electrospinning is used to produce very long helical polystyrene microfibers in water. The pitch length of helices can be controlled by changing the applied voltage, allowing to produce both micro springs and microchannels. Using a novel high frequency variable voltage electrospinning method we found the helix formation speed and compared the experimental buckling frequency to...

We study the buckling of a thin compressed elastic film bonded to a compliant substrate. We focus on a family of buckling patterns, such that the film profile is generated by two functions of a single variable. This family includes the unbuckled configuration, the classical primary mode made of straight stripes, as well the pattern with undulating stripes obtained by a secondary instability inv...

Steel plate shear walls (SPSWs) in buildings are known to be an effective means for resisting lateral forces. By using un-stiffened walls and allowing them to buckle, their energy absorption capacity will increase significantly due to the postbuckling capacity. The post-buckling tension field action of SPSWs can provide substantial strength, stiffness and ductility. This paper presents the Fini...

Hollow sections have been widely used for steel structures. Applications of High Strength Steel (HSS) on cold-formed hollow sections lead to thinner and lighter structures. This paper presents numerical investigations on the lateral-torsional buckling resistance of the cold-formed high strength steel rectangular hollow beam. Results from finite element analysis using Abaqus software are compare...

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...

We present a detailed asymptotic analysis of the point indentation of an unpressurized, spherical elastic shell. Previous analyses of this classic problem have assumed that for sufficiently large indentation depths, such a shell deforms by 'mirror buckling'-a portion of the shell inverts to become a spherical cap with equal but opposite curvature to the undeformed shell. The energy of deformati...