<p style="text-align: justify;">Mixed-mode fracture in delamination test utilizing double cantilever specimens loaded with bending moments is investigated in the paper. FEM simulations are performed using cohesive zone model where different configurations of test loadings and two critical fracture energy values, ie. two fracture process zone lengths, are considered. Fracture energy partitioning is performed and fracture mode-mixity is determined using simulation results, i.e. mode I and mode II fracture parts in total fracture energy are calculated. The fracture mode-mixities numerically determined for different configurations are compared with results obtained using two analytical fracture energy partitioning theories, according to Williams and to Hutchinson and Suo. An excellent agreement between numerical and the analytical results is observed.</p>

Delamination (fracture) tests have been numerically investigated using various cohesive zone properties. The test utilises asymmetric and symmetric double cantilever beam specimens loaded with bending moment. Energy release rate contributions from mode I and mode II fracture are calculated using a global and local approach. Mode-mixities results are presented and analysed. The numerical partitioning results for different configurations are compared to two analytical partitioning theories, namely, after Williams and after Hutchinson and Suo. Opposite to these theories, partitioning is observed to be dependent on cohesive zone properties.

Abstract This paper describes a finite volume method for orthotropic bodies with general principal material directions undergoing large strains and large rotations. The governing and constitutive relations are presented and the employed updated Lagrangian mathematical model is outlined. In order to maintain equivalence with large strain total Lagrangian methods, the constitutive stiffness tensor is updated transforming the principal material directions to the deformed configuration. Discretisation is performed using the cell-centred finite volume method for unstructured convex polyhedral meshes. The current methodology is successfully verified by numerically examining two separate test cases: a circular hole in an orthotropic plate subjected to a traction and a rotating orthotropic plate containing a hole subjected to a pressure. The numerical predictions have been shown to agree closely with the available analytical solutions. In addition, a 3-D composite component is examined to demonstrate the capabilities of the developed methodology in terms of a variable material orientation and parallel processing.

This paper establishes a procedure for numerical analysis of a hip joint using the finite volume method. Patient-specific hip joint geometry is segmented directly from computed tomography and magnetic resonance imaging datasets and the resulting bone surfaces are processed into a form suitable for volume meshing. A high resolution continuum tetrahedral mesh has been generated, where a sandwich model approach is adopted; the bones are represented as a stiffer cortical shells surrounding more flexible cancellous cores. Cartilage is included as a uniform thickness extruded layer and the effect of layer thickness is investigated. To realistically position the bones, gait analysis has been performed giving the 3D positions of the bones for the full gait cycle. Three phases of the gait cycle are examined using a finite volume based custom structural contact solver implemented in open-source software OpenFOAM.

Original scientific paper This paper presents an analysis of the stress distribution on the outer surface of the riding ring of rotary cement kiln during working cycle using both the theory and finite element simulation. In the theoretical analysis, the total stress is obtained as a combination of bending, thermal and contact stresses. To obtain bending stress the kiln is considered as a simply supported, indeterminate beam subjected to static and symmetrical loads and Castigliano’s theorem is employed. Thermal stresses are obtained assuming both linear and non-linear temperature distribution over the ring thickness. Contact stress between ring and supporting rollers is obtained using Hertz contact theory. Bending, thermal and contact stresses are also obtained numerically in separate simulations, mimicking conditions assumed in the theoretical part. All results are in excellent agreement. In addition, a more realistic ring model subjected to all loads simultaneously is also simulated. These results showed slight disagreement with theory in the contact region, mainly due to sliding contact between the roller and the ring, but overall agreement was good.