The initiation and growth of instabilities in granular materials loaded by air shock waves are investigated via shock-tube experiments and numerical calculations. Three types of granular media, dry sand, water-saturated sand and a granular solid comprising PTFE spheres were experimentally investigated by air shock loading slugs of these materials in a transparent shock tube. Under all shock pre...

Among different discretization approaches, Finite Difference Method (FDM) is widely used for acoustic and elastic full-wave form modeling. An inevitable deficit of the technique, however, is its sever requirement to computational resources. A promising solution is parallelization, where the problem is broken into several segments, and the calculations are distributed over different processors. ...

OBJECTIVE The purpose of this study was to determine the fracture strength of zirconium implant abutments and the torque required to unfasten the retaining screw before and after applying cyclic loading to the implant-abutment assembly. The dynamic behavior and stress distribution pattern of zirconium abutments were also evaluated. METHODS AND MATERIALS Static and cyclic loading of 7 XiVE imp...

Mansuri oil field, which is located at the South-West of Iran, has sand production problem and primary analyses proved the existence of this phenomenon in this field. Generally, there are three methods to evaluate the sand production state which are empirical, numerical, mathematical, and physical. Considering the numerical capability to analyze complex geometries under high stresses condition,...

A numerical solution for heave prediction is developed within the context theories for both saturated and unsaturated soil behaviors. Basically, lowering the potential level of compressing on a saturated layer will cause heaving due to water absorption. This water absorption is in an opposite way, similar to water dissipation as what happens during unloading in consolidation process. However, i...

This study applies artificial neural networks (ANN) to simulate the soil stress-strain relationship observed in test data from triaxial shear testing of saturated sand. A genetic algorithm is used to obtain an optimal framework for the ANN. The results show that the proposed genetic adaptive neural network (GANN) can effectively model undrained monotonic and cyclic triaxial behaviour of saturat...

application of outflow water from treatment plants for irrigation as a non-usual water resource is being developed due to the lack of usual water resources in iran. activated carbon as a conditioner in water treatment procedures causes undesired changes in hydraulic properties of porous media and soil degradation. in this paper, the effects of activated carbon concentration on hydrodynamic prop...

study on the seismic behavior of piled rafts and pile groups while the same amount of construction material and excavation is used in their construction, are the main objective of this research. the process where the raft interaction with soil can affect the seismic response and stress distribution is also discussed in the current study. by means, abaqus software was applied for the finite elem...

The numerical simulation of shallow water acoustic propagation has given rise to a wide variety of modeling techniques with various degrees of accuracy. One technique, involving finite difference methods, is more commonly used in the description of seismic propagation but also occurs in the shallow water propagation literature. This word reported here involves the application of finite differen...