Published in Frontiers in Physics
Experiments, simulations, and theoretical treatments of granular materials typically feature circular or elliptical grains. However, grains found in natural systems often have flat faces that introduce local rotational constraints; these rotational constraints have been shown to affect, for example, the jamming transition, discontinuous shear thick...
Published in Classical and Quantum Gravity
With a relative length measurement precision of better than 10−23, gravitational wave interferometers are the most precise instruments that have ever been built. With this enormous sensitivity many noise sources potentially effect gravitational wave detector sensitivity, each of which must be investigated to ensure confidence in design sensitivity....
Published in The Journal of oral implantology
This study aimed to test and compare 2 novel dental mini-implant designs to support overdentures with a commercial model, regarding the stress distribution, by photoelastic analysis. Three different mini-implant designs (Ø 2.0 mm × 10 mm) were tested: G1-experimental threaded (design with threads and 3 longitudinal and equidistant self-cutting cham...
Published in Journal of endodontics
Structural defects created by endodontic treatment are the most common cause of major dental failures. This study analyzed levels of stress produced by endodontic instruments during the root canal treatment by photoelastic analysis of stress. Twenty-four human premolars were randomly divided into 4 groups (n = 6) according to instrumentation protoc...
Published in Polymer Science, Series D
AbstractThe theory is proposed for solving problems of adhesion mechanics that is based on the concept of an anisotropic layer that serves as a contact between the adhesive and substrate. All boundary conditions in contact problems and the original equations are satisfied exactly; i.e., the mathematical Cauchy problem is solved. The possibilities o...
Photoelasticity offers a promising measurement tool for the in-line measurement of semiconductor materials such as silicon. Photoelasticity is a contactless, optical and full-field measurement method based on stress-induced birefringence. However, it is in principle only capable of measuring stress differences and therefore not able to determine th...
Published in Polymers
Eight types of polyurethane were synthesized using seven types of diisocyanate. It was found that the elasto-optical constant depends on the concentration of diisocyanate groups in a unit volume of a polymer and the magnitude of anisotropy of the dielectric constant of diisocyanate groups. It was also found that incident light scattered when bendin...
Published in Polymers
The effects such as warpage, dimensional instability and environmental stress corrosion, due to the presence of residual stresses in polymeric products, are strongly dependent on injection molding conditions. The holding time and holding pressure belongs to most important processing parameters, determining the dimensional stability and properties o...
Published in Journal of Polymer Engineering
The digital photoelastic technique is used to characterise the necking behaviour of isotactic polypropylene (iPP) fibres. The effect of stretching rate on necking initiation is studied. The birth of necking is observed using photoelastic patterns of the stretched fibres to understand how the localised difference between the principle stresses grows...
The photoelastic effect was used to visualize and quantify stresses at the end of fibers embedded in birefringent epoxy resin. A method was proposed allowing not to only quantify the differences in main principal stress for a single loading state, but to allow monitoring the evolution of local stress throughout the micro-mechanical experiment. It w...
