stress state

Influence of friction characteristics of a bulk material on its outflow from a conical hole

Taking into account the adhesive interaction of the product with the walls of the hopper, a mathematical model of the fine-grained bulk material stress state in a conical hopper hole under vibration is proposed.  A discrete environment model was used for analysis.  This model was based on considering the equilibrium of an elementary volume with an infinitesimal thickness.  An analytical dependency was established, allowing an estimate of the influence of frictional factors on the fine-grained bulk material stress state, thereby enabling its modification by adjusting cer

Use of a complex of gas-ground surveying and geophysical research for solving the problem of defining the territory of mud volcanism within Rozvadiv area in Lviv oblast

The purpose of the research was to substantiate the scientific basis behind the formation of a mud volcano within a specific section of the Precarpathian depression. It also aims to examine the existence of a near-fault shallow gas deposit in the Rozvadiv area and its possible impact on gas-soil surveying and electrometry fields. The relevance of the work is determined by the need to solve the ecological problem of environmental pollution with hydrocarbon gases, as well as to establish and forecast the degree of emissions of the gas-mud mixture.

Display of mechanical stresses' distribution in mining areas in the intensity dynamics of the Earth's natural pulsed electromagnetic field

The purpose of the research is to substantiate the theoretical prerequisites for the interpretation of the geophysical method of the Earth's natural pulsed electromagnetic field (ENPEMF). The justification will be performed by quantifying the stress state of the rock massif, modeling of the obtained analytical dependencies for disturbed massifs. The basis for the interpretation is the coordination of the obtained distributions of intensity with the intensity of the electromagnetic field.

Modeling of a bulk material stress state in a conical hopper hole under vibration action

A model of a fine-grained bulk material stress state in a conical hopper hole under vibration during material unloading is proposed.  For the study, it is used a model of a discrete medium based on a balance of a small thickness elementary volume, in which the stress redistribution occurs by opening an outlet at the hopper bottom.  A formula for determining the material radial stress in the discharge conical hopper hole is obtained, taking into account all force factors influencing the bulk material behavior.  The influence of humidity, shape and geometric parameters of the hopper, and vibr

Assessment of suitability of screen tubes with damages for further use on the basis of mathematical modeling

Computer simulation of the processes of deformation of screen tubes of boiler units at a thermal power station with wall thinning due to the intense influence of flue gases has been carried out.  The dependences between the maximum stresses in the screen tubes with operational thinnings and the geometrical parameters of the damaged areas of the tubes have been constructed, which allow us to determine the minimum thickness of tubes, for which operating stresses do not exceed a given permissible level.

Reconstruction of the tectonic stress field before and after Japan earthquake 11 march 2011

Purpose. The purpose of the research is to study the features of the tectonic stress field before and after the 2011 Japan earthquake. Methodology. The reconstruction of the tectonic stress field is carried out on the basis of cataclastic analysis method of earthquake focal mechanism. The method allows us to define the tectonic stress tensor parameters and increments of quasi-plastic deformation. Results.