Experimental identification of the material standard linear solid model parameters by means of dynamical measurements

A procedure for the experimental identification of the material standard linear solid model parameters by means of dynamic mechanical analysis test instrument measurements is presented. Since the standard linear solid material stress–strain functional D( ω) relationship in the frequency domain formally depends on the standard linear solid material parameters, a procedure able to identify these parameters from test measurement estimates is proposed in this work. Nevertheless, a critical, nonlinear and non-parametric approach is to be followed since the number of the material standard linear solid block components is generally unknown, and the material D( ω) shows a highly nonlinear dependency on the unknown standard linear solid material parameters. For these reasons, measurement and test model noise is expected to strongly influence the accuracy of the identification results. A multi-step procedure is presented, consisting first in the non-parametric identification of a frequency dependent, two degrees of freedom model instrument frame by means of a polynomial rational function, where polynomial order and parameters, such as polynomial coefficients and pole-residue couples, are optimally identified by means of an algebraic numerical technique and of an iterative stabilization procedure. Another procedure able to identify the material D( ω) polynomial rational functional relationship in the frequency domain is also proposed, taking into account the dynamic contribution of the instrument frame, of the inertial contribution of the distributed mass of the beam and of the lumped mass of the instrument force measuring system. An effective procedure, able to identify the standard linear solid material model parameters in the time domain from the identified material physical poles, is finally proposed. Some application examples, concerning the identification of the standard linear solid model of a known material and of an unknown composite material, are shown and discussed as well.

TRANSFORMATION OF CURRENT ISSUES OF MODERN SOCIO-POLITICAL CHANGES

The article provides estimates of the “material standard of living” of the world’s population by periods (life expectancy, the volume of production of consumer goods, services, and products per capita). Many scientists and experts, politicians and, statesmen who have left their mark on world history have thought about the concept of progress. Most of them supported the idea of “progress” only from the bottom up. One described the pinnacle of progress as Chinese communism and, another called it “Western democracy.” This one-sided explanation reflects in the theory of five entities. (primitive, slavery, feudalism, capitalism and, communism or Western democracy). It emphasizes that all nations must go through these formations. The end of the twentieth century was characterized not only by the breakdown of the socialist system so “longawaited” in the West, the disappearance of the bipolar world and the emergence of world centers of power, unpredictable insane globalization with all the ensuing consequences, but, as it is obvious now, by the emergence of new, previously unseen threats and challenges not only to the sovereignty of individual countries but, above all, by threats to the existence of both each individual and by challenges to the existence of people itself. The first quarter of the 21st century, more than ever before, stuck out, exposed and, brought to the culmination point all painful problems - environmental, economic, geopolitical, socio-cultural, etc. The problem of adequate analysis and forecasting of these threats and challenges did not test, methodologically verified. The study made it possible to conclude that the issue of global and national security on earth is one of the main tasks of any state. And the understanding of the current requirements plays a principal role in preventing the emergence of a threat factor. Thus, understanding the period is one of the dominant needs in preventing the emergence of a threat factor

DESOCIALIZATION, DEHUMANIZATION AND SOCIAL DEPRIVATION OF THE INDIVIDUAL, AS LINKS IN ONE CHAIN

В данной статье говорится о том, что дегуманизация, десоциализация и депривация являются следствием социально-экономических трудностей в государстве, что в свою очередь может привести к низкому духовному и материальному уровню жизни, и обезличиванию личности. This article States that dehumanization, desocialization and deprivation are the result of socio-economic difficulties in the state, which in turn can lead to a low spiritual and material standard of living, and depersonalization of the individual.

Environmental consequences of COVID-19 on the global and Russian economics

In the article, the environmental consequences of COVID-19 are divided into three groups: negative, positive and ambiguously interpreted. Over the coming years, we can expect a weakening of the attention of the state, business and the population towards environmental issues, a decrease in environmentally oriented costs, redirection of cash flows to maintain or prevent a significant drop in the material standard of living. Among the conditionally positive consequences of COVID-19 and the associated economic crisis, one can single out a short-term reduction in the environmental impact, awareness of the increasingly urgent need for an early change in the export-raw material model, and the requirement for international coordination.

Testing of Welded Joints between Pipes for Pressure Vessels Made of Hot Rolled Fine-Grained Steel P460NL1

This paper contains results of tests performed in order to determine mechanical properties of steel P460NL1, used as filler material during the execution of welded joints. Arc welding of samples from which the specimens were taken was carried out through the application of welding process 111, because it is one of the processes for the execution of pipelines for pressure equipment. Microspecimens with diameter of Ø1,5 mm were tested in order to determine tensile properties of material taken from the heat-affected zone and weld metal, while specimens with diameter of Ø6 mm were tested in order to determine tensile properties of parent material. Standard Charpy V-notch specimens were used in order to determine impact energy. Results of metallographic tests which refer to the structure of a pipe welded joint are also presented.

The Influence of Annealing and Normalizing Processes on the Mechanical Properties and Chemical Composition of Carbon Steel ASTM A285Gr.C

Paper Carbon steel ASTM A285 Grade C it’s easy to use and has all the material properties that are suitable for many purposes. One of the most metallurgical processes is heat treatment. Heat treatment on carbon steel is to improve ductility, toughness, strength, hardness and tensile strength and to relieve internal stress developed in the material. This paper describes the effect of rising temperature change on the mechanical properties of specimens. Two important processes of heat treatment are achieved in this paper; First heat treatment process is "Annealing" that involves heating specimens gradually in a furnace above several 723 °C and then soaking it in the furnace and then cooled inside the furnace. "Normalizing" is a second process that also involves heating the specimens gradually in a furnace above several 723 °C and soaking it in the furnace followed by cooled in the air. The specimen prepared according to ASTM (American Society for Testing and Material) standard. With increasing the temperature of the annealing process the strength of the specimens is decreased until it reached around 350 MPa at 1000 °C. Through the chemical composition of the specimen after the heat treatment process and compared with nominal compositions observed that the specimens loosed elements.

Child poverty in rich contexts: The example of Sweden

In international comparisons, Sweden is one of the countries with the lowest number of children growing up in poverty; its material standard is high, and welfare services are extensive and heavily subsidised. How child poverty can be understood in that context is interrogated in the article. The point of departure for the discussion is Swedish Save the Children’s 2013 anti-poverty campaign Fattigskolan [Poverty School]. The campaign presents child poverty from the vantage point of a welfare state and is informative for understanding normative discourses on childhood. Childhood is investigated as a social imagination that both structures children’s and parents’ everyday lives and organises society. It is argued that the dominant social imagination is based on a middle-class fantasy permeating the organisation of the welfare state. The elements of this fantasy are critical to understanding child poverty.