Cylindrical shells under uniaxial compression and spherical shells under equi-biaxial compression display the most extreme buckling sensitivity to imperfections. In engineering practice, the reduction of load carrying capacity due to imperfections is usually addressed by use of a knockdown factor to lower the critical buckling stress estimated or computed without accounting for imperfections. F...

A laser vibrometry based dynamic technique for biaxial residual stress determination in micromembranes is reported. Layered, low pressure chemical vapor deposition (LPCVD) grown, rectangular shaped micromernbranes are ultrasonically excited. The resulting micrornembrane displacement, as a function of frequency and position, is recorded to yield resonance frequencies and associated vibrational m...

Interconnects are susceptible to solid diffusion under residual stress, electric current, and elevated temperature. As atoms diffuse, voids nucleate, drift, and enlarge. At some point, the voids of rounded shape can collapse to narrow slits and sever the interconnects. The fatal slits are often found to be transgranular, i.e., each slit cuts across a single grain. They have raised many concerns...

BACKGROUND Temporary cold storage is a common procedure for preserving tissues for a short time before using them in a clinical or experimental setting. The process of storing tissues at refrigeration or freezing temperatures can affect the mechanical properties of the tissue. Previous studies were limited to uniaxial tensile tests and did not have substantial explanations for what was structur...

Steel plates in double skin composite (DSC) panels are restrained by a concrete core and welded stud shear connectors at discrete positions. Local buckling of steel plates in DSC panels may occur in a unilateral mode between stud shear connectors when subjected to combined states of stresses. This paper studies the local and post-local buckling strength of steel plates in DSC panels under biaxi...

An original experimental facility for studying the physical properties of materials during elastic-plastic deformation along two axes has been created. The no ferromagnetic parts in working area, thus enabling us to make more accurate magnetic measurements. Biaxial is simulated by finite element method order optimize geometry specimen and determine stress state central zone specimen. Test exper...

Cathodoluminescence CL measurements of the ground-state excitonic transition of vertically stacked GaN /AlN quantum dots QDs exhibited an in-plane linear polarization anisotropy in close proximity to microcracks. Microcracks form as a result of a mismatch of the thermal expansion coefficient between the GaN /AlN layers and the Si 111 substrate. In close proximity to the cracks, the layers are f...

Lung parenchyma surrounding an atelectatic region is thought to be subjected to increased stress compared with the rest of the lung. Using 37 hexagonal cells made of linear springs, Mead et al. (1970) measured a stress concentration greater than 30% in the springs surrounding a stiffer central cell. We re-examine the problem using a 2D finite element model of 500 cells made of thin filaments wi...

A method utilizing expansion of a diaphragm-type film specimen was developed to study in vitro biodegradation of poly(etherurethane urea) (PEUU) under conditions of dynamic loading (fatigue). A finite element model was used to describe the strain state, which ranged from uniaxial at the edges of the film to balanced biaxial tensile strain at the center. During testing, the film was exposed to a...

Mining at greater depths can lead to stress-induced failure, especially in areas of high horizontal in-situ stress. The induced stresses around the opening are known be a poly-axial stress state where, σ_1≠ σ_2≠ σ_3 with special case σ_3= 0 and σ_1, σ_2 ≠ its boundary. conventional triaxial testing does not represent actual strength rock regions stress, as it ignores influence intermediate prin...