The aim of this paper is to determine the critical buckling load for simply supported thin shallow spherical shells made of functionally graded material (FGM) subjected to uniform external pressure. A metal-ceramic functionally graded (FG) shell with a power law distribution for volume fraction is considered, where its properties vary gradually through the shell thickness direction from pure me...

New experimental results show that laser bending can be extended to generate a bending angle not only towards but also away from the laser beam, giving more flexibility to the process. In order to explain this buckling instability, a series of experiments have been carried out with real-time measurement of the bending angle for different materials, thicknesses, scanning speeds, laser beam diame...

Failure in cold-formed steel beams is generally initiated by one of three instabilities: local, distortional, or lateral-torsional buckling. For cold-formed steel joists, purlins, or girts, when the compression flange is not restrained by attachment to sheathing or paneling, distortional buckling may be the predominant failure mode. Experimental results on cold-formed steel beams with unrestrai...

The cytoskeleton provides the mechanical scaffold and maintains the integrity of cells. It is usually believed that one type of cytoskeleton biopolymer, microtubules, bears compressive force. In vitro experiments found that isolated microtubules may form an Euler buckling pattern with a long-wavelength for very small compressive force. This, however, does not agree with in vivo experiments wher...

The strength of sheathed wall systems is substantially greater than unsheathed walls with the same studs. Testing on studs sheathed on both sides with dry gypsum board demonstrate strength increases as large as 70% over unsheathed studs (Miller and Peköz 1993, Miller and Peköz 1994). The current AISI Specification for sheathed wall stud systems are complicated, only apply when the sheathing is ...

We report on molecular dynamic calculations of combined tension–torsion of chiral single-wall nanotubes. We work within the framework of objective structures that exploits symmetry groups to enable torsion of chiral nanotubes, in addition to non-equilibrium extension. We apply the method to study the mechanical response and failure of nanotubes of various chiralities. We find that three distinc...

Linear eigenvalue analysis of cracked cylindrical shells under combined internal pressure and axial compression is carried out to study the effect of crack type, size and orientation on the buckling behavior of cylindrical thin shells. Two types of crack are considered; through crack and thumbnail crack. Our calculations indicate that depending on the crack type, length, orientation and the int...

We report the results of a numerical and theoretical study of buckling in elastic columns containing a line of holes. Buckling is a common failure mode of elastic columns under compression, found over scales ranging from metres in buildings and aircraft to tens of nanometers in DNA. This failure usually occurs through lateral buckling, described for slender columns by Euler's theory. When the c...

In this paper we develop vacuum-actuated polyimide bi-stable actuators using buckled diaphragms for applications in the field of MEMS. The fabrication process involves a single mask step and DRIE etch step to fabricate the buckled bi-stable diaphragms. Compressive stresses in a companion thermal oxide layer provide pre-stress in the polyimide mechanical films that initiates diaphragm buckling u...

Freeze casting with isopropanol (IPA)–H2O as a freezing agent has shown the potential to create porous scaffolds with enlarged pores. Though not experimentally proven, this effect has been suggested to be the result of non-stoichiometric structures called clathrate hydrates forming during the freezing process. In this manuscript, we build upon these results to provide experimental evidence of t...