The wide-gap aluminothermic rail welds with root opening of 50-70 mm were produced using plain carbon steel rail and non-alloy aluminothermic charge. Mechanical properties and micro-structure of the weld metal and HAZ as well as the impact energy and the fracture toughness of the welds were investigated. The yield and tensile strength of wide-gap welds were about 98% and 95% of the base metal, ...

Schallamach’s theory of rate-dependent bond dissociation is used to understand the fracture of a polymerglass interface. The model system consists of an elastomeric film (20 μm thick) of poly(dimethylsiloxane), chemically bonded to a silanized glass substrate. The fracture energy of the interface varies logarithmically with velocity, which is consistent with Schallamach’s theory of forced bond ...

background: trans-scaphoid perilunate fracture-dislocation and perilunate dislocations are among uncommon injuries, most commonly seen in young patients due to high energy trauma. the treatment can be achieved either surgically by open reduc tion and internal fixation or closed reduction and casting.   methods: to compare surgical versus non-operative results of treatment of trans-scaphoid peri...

The final shape of natural minerals as raw materials is determined by its genesis, by its chemistry, its crystal structure and by the grinding processing it has undergone [1]. The mineral rupture involves several different processes occurring together or successively. As an approximation, during the comminution of phyllosilicates, two distinct breakage processes occur: the breakage is parallel ...

The effect of thermal treatment on spruce is examined by analyzing the fracture and hygroscopic properties. Specimens were heated at temperatures within the range 120-200 °C for 1 h. Fracture energy was measured using a single-edge notched bending test and the strain-softening index was estimated by dividing the fracture energy by the maximum load. Adsorption properties were estimated using ads...

We have carried out systematic fracture experiments in a single edge notch geometry over a range of stretch rates on dual crosslink hydrogels made from polyvinyl alcohol chains chemically crosslinked with glutaraldehyde and physically crosslinked with borate ions. If the energy release rate necessary for crack propagation was calculated conventionally, by using the work done to deform the sampl...

In this paper we analyze a two-dimensional discrete model of nearestneighbour Lennard-Jones interactions under the microscopical constraint that points on a lattice triangle maintain their order. This can be understood as a microscopical non-interpenetration constraint and amounts to the positiveness of the determinant of the gradient of the piecewiseaffine interpolations of the discrete displa...

Sacral fracture commonly results from high-energy trauma. Most insufficiency fractures of the sacrum are seen in women after the age of 70. Fractures of the sacrum are rare and generally combined with a concomitant pelvic fracture. Transverse sacral fractures are even less frequent which constitute only 3-5% of all sacral fractures. This type of fractures provide a diagnostic challenge. We repo...

Introduction Thin polymer fi lms are fi nding increasing interest in biological sciences and semiconductor packaging, along with their popular application as packaging materials. Researchers also show interest in studying mechanical stresses and fracture behavior in soft biological materials [1, 2]. In many of these applications, the fi lms need to experience severe mechanical stresses during h...

Accurate assessment of hip fracture risk is very important to prevent hip fracture and to monitor the effect of a treatment. A subject-specific QCT-based finite element model was constructed to assess hip fracture risk at the critical locations of femur during the single-leg stance and the sideways fall. The aim of this study was to improve the prediction of hip fracture risk by introducing a n...