A dislocation segment in a crystal experiences a 'self-force', by virtue of the orientation dependence of its elastic energy. If the crystal is elastically isotropic, this force is manifested as a couple acting to rotate the segment toward the lower energy of the pure screw orientation (i.e. acting to align the dislocation line with its Burgers vector). If the crystal is anisotropic, there are ...

INTRODUCTION Posterior dislocation of the hip joint with associated acetabular and intertrochanteric fracture is a complex injury. Early recognition, prompt and stable reduction is needed of successful outcome. CASE REPORT 45 year old male patient presented with posterior dislocation of the hip with transverse fracture with posterior wall fracture of acetabulam and intertrochanteric fracture ...

Local electronic properties of quasi-two-dimensional Pb(111) islands with screw dislocations different types on their surfaces were experimentally studied by means low-temperature scanning tunneling microscopy and spectroscopy in the regime constant current. A comparison topography map, maps current variation differential conductance acquired simultaneously allows one to visualize hidden parts ...

∑ 3{111} coherent twin boundary (CTB) in face-centered-cubic (FCC) metals and alloys have been regarded as an efficient way to simultaneously increase strength and ductility at the nanoscale. Extensive study of dislocation-CTB interaction has been carried out by a combination of computer simulations, experiments and continuum theory. Most of them, however, are based on the perfect CTB assumptio...

This study conducts the modeling and numerical analysis of a screw dislocation in three-dimensional continuous medium. Our is based on differential geometry Weitzenböck manifold, i.e., Riemann-Cartan manifold which equips itself with non-zero torsion affine connection. Following to standard framework geometrical elasto-plasticity, we introduce three smooth manifolds representing reference R, in...

We introduce and discuss discrete two-dimensional models for XY spin systems and screw dislocations in crystals. We prove that, as the lattice spacing ε tends to zero, the relevant energies in these models behave like a free energy in the complex Ginzburg-Landau theory of superconductivity, justifying in a rigorous mathematical language the analogies between screw dislocations in crystals and v...

The strength of pedicle screws attachment to the vertebrae is an important factor affecting their motion resistance and long term performance. Low bone quality, e.g. in osteopenic patients, keeps the screw bone interface at risk for subsidence and dislocation. In such cases, bone cement could be used to augment pedicle screw fixation. But its use is not free of risk. Therefore, clinicians, espe...

In order to evaluate the hydrogen-defect interactions, an internal friction study is performed on hydrogen-charged cold rolled ultra-low carbon steel. For this purpose, steel subjected various thermo-mechanical treatments and information hydrogen-dislocation interactions are obtained via thorough analysis of so-called hydrogen work peak by friction. Using existing theoretical models, could be d...

In this article, the anti-plane deformation of an orthotropic sector with multiple defects is studied analytically. The solution of a Volterra-type screw dislocation problem in a sector is first obtained by means of a finite Fourier cosine transform. The closed form solution is then derived for displacement and stress fields over the sector domain. Next, the distributed dislocation method is em...

Dislocation dynamics simulations of the interaction between prismatic dipolar loops and a glide screw dislocation are presented. As a result of stress gradients generated by the glide dislocation, dipolar loops execute drift motion along their glide cylinders. Simulations of the combined motion of two dipolar loops in the stress field of a glide dislocation clearly show that inter-loop forces a...