where δif only needs to be accounted for if the applied loads influence the virtual crack rotation, e.g. due to crack face tractions and body-type loads. Also, it is worth observing that, non-zero contributions to the variations δiK, δif occur only in those elements that experience the virtual crack rotation. The rates of the energy release rate, Hsij are obtained by differentiating Gsi in (5) ...

Fatigue crack growth behavior of AZ61 magnesium alloy was investigated in low humidity (55% relative humidity) and 3.5% NaCl spray environments under various stress ratios. Fatigue crack growth rates became higher with increasing load ratio for both environments. However, the results of fatigue crack growth test under 3.5% NaCl spray environment showed lower fatigue crack propagation rate compa...

We used a rabbit model to investigate the mechanism by which the angulation of fractures is corrected in children. We produced a transverse proximal tibial fracture in one leg of 12 eight-week-old New Zealand white rabbits and measured bone alignment and length and the patterns of bone growth and remodelling. The angle between the joint surfaces changed rapidly to correct the alignment of the l...

Concrete is a so called quasibrittle material which, despite predominantly elastic material response, exhibits in tension loading a stable non-linear fracture response, when tested under displacement control. The reason for the non-linearity is the development of a fracture process zone, in front of the crack, due to micro-cracking and crack bridging. The effect of the fracture process zone is ...

The intergranular crack propagation of the lamellar structure β titanium alloys is investigated by using a modified Gurson-type damage model. The representative microstructure of the lamellar alloy, which consists of the soft α phase layer surrounding the hard grain interiors, is generated based on an advanced Voronoi algorithm. Both the normal fracture due to void growth and the shear fracture...

Mode I, quasi-static, steady state crack growth is analyzed for rate dependent materials under plane strain conditions in small scale yielding. The solid is characterized by an elastic-viscoplastic constitutive law and the plane ahead of the crack tip is embedded with a rate dependent fracture process zone. The macroscopic work of fracture of the material is computed as a function of the crack ...

A continuum damage mechanics (CDM) based constitutive model has been developed to describe elastic, plastic and damage behavior of porous rocks. The pressure sensitive inelastic deformation of porous rocks together with their damage mechanisms are studied for drained and undrained conditions. Fracture mechanics of microcrack andmicro-void nucleation and their coalescence are incorporated into t...

conclusions in this experimental model of open fracture, the chitosan film pure or impregnated with ciprofloxacin was not effective in the prophylaxis of osteomyelitis. results in cultures of the ct group, there was less bacterial growth compared to the results of the cultures of the ic (p = 0.005), c (p = 0.005) and ca (p = 0.009) groups. the inflammation was lower in the ct group compared to ...

Bone strength is, in part, dependent on a mechanical input that regulates the (re)modelling of skeletal elements to an appropriate size and architecture to resist fracture during habitual use. The rate of longitudinal bone growth in juveniles can also affect fracture incidence in adulthood, suggesting an influence of growth rate on later bone quality. We have compared the effects of fast and sl...