International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This work deals with corrosion measurements of galvanized steel HCT600X+Z subjected to progressively increasing plastic strain. The corrosion resistance measurements were carried out by non-destructive EIS (electrochemical impedance spectroscopy) test and destructive LP (linear polarization) test. As a result of the work, the measured data were analyzed and the results were processed using Nyquist diagram and Tafel analysis.

This paper investigates stress state in connection of pipes with flat ends used in pressurized pipelines and steam boiler connections. Flat ends are designed according standard EN 12952-3 and later numerically checked using linear elastic material model. These analyses showed areas with increased stress. Therefore, additional analyses were performed using linear elastic-ideally plastic material. The maximal pressure loads are obtained for series of pipes with flat ends and compared to calculated results according EN 12952-3 norm.

As a result of the conducted theoretical and experimental researches of the local state of strains at the most loaded intersection of the clamps on the working wheel’s carrying structure in a concrete rotating excavator, an array of results has been attained. This paper represents systematically by means of diagrams the results of such researches under normal and specific working regimes of the excavator.

The specific working regimes during the entire exploitation life of the excavator account for about 1 %, with the excavator working in specific cases while digging under unpredictable working conditions. The experimental magnitudes of the strains are obtained with conducted experimental measurement in compliance with the established methodology for this purpose. The theoretical magnitudes of the strains are derived using the established mathematical model of clamps and applied computer FEM analysis.

The analysis of stress-strain state of the bisector of the corner of the blank at a drawing of box-shaped parts. Analytical dependences for the meridional and circumferential stress on the bisector of the angle. It is shown that an increase in the limit drawing ratio compared with an extract of the cylindrical part is a consequence of the growth in absolute value of district compressive stresses. It was found that the maximum value of the coefficient of drawing of box-shaped parts cannot exceed the value of – K=exp(1+1/√3)≈ 4,84.

In tensile machines to measure the change in length of the specimen during the stress, most time extensometer and various contact methods and tools, such as strain gauges are used, but these methods have limitations and low accuracy that cause unexpected and different results from the theoretical values for the strain. In this paper, to address this shortcoming and improve strain measurement, a non-contact method using image processing techniques in the MATLAB environment is introduced. for this purpose after capturing a move of tensile test and converting that in to some high quality pictures and using image processing we put some pattern in the first image and with using a special algorithm with name of Digital Image Correlation (DIC) detect that patterns until the last image then we can use of displacement algorithm and calculate change in the specimen’s length and after that we can also have “Strain” with using these values.

Based on the analysis of the initial equations of the plastic state,established the distribution of strains in the initial and final stages of axisymmetric drawing. The dependencies to assess the accuracy of linear and diametrical sizes taking into account volumetric of strain state.

By using visioplasticity method the velocity field can be determined experimentally, and then the stresses can he obtained analytically from these experimental measurements. That means, strain rates and strains are calculated directly from the velocity field while the stress distribution is calculated from an analytical solution of the equilibrium equations and the constitutive equation relating the stress and strain for the material. This method can also provide detailed data of the pressure distribution on the die surface, which is important in the design of the die profile. In the paper cold forward extrusion through a conical die is illustrated by extruding copper alloy specimens with inscribed grid lines. Stress state distribution in plastic deformation region was analyzed using the visioplasticity method. From the flow lines of each element, the velocity and the strain rates are obtained. Finally, the stress components are calculated from the equilibrium and plasticity equations.