GRP Structures Research Articles

Statistical Analysis of the Socio-Economic Situation in St. Petersburg in the Context of Crises

Purpose of the study. Statistical research of the socio-economic development issues of the region acquires special significance in crisis situations. Statistical methods make it possible to quantify the current situation, identify the impact of crisis phenomena and forecast the development of the region. In the analysis of socio-economic development, both economic characteristics (GDP, production and distribution) and direct indicators of the standard of living of the population (unemployment level, personal income and wages) are the key ones. The purpose of this paper is to statistically assess the impact of crisis situations on the socio-economic situation in St. Petersburg.Materials and methods. The information base for the study was official data from the Federal State Statistics Service. The paper uses methods of time series analysis, cluster analysis and analysis of structural changes.Results. Based on the results of the study, the main periods in the dynamics of the main socio-economic indexes were identified. Special attention is paid to studying the structure of GRP of St. Petersburg. Emphasis is placed on comparing the dynamics of regional indexes with data for the federal district and the Russian Federation as a whole. The features of the city’s development are considered using cluster analysis according to the current range of factors for different time periods. An assessment of the achievement of key planned indexes is given and a comprehensive index is proposed for assessing the development of the dynamics of the socio-economic development of the region. Particular attention is paid to analyzing the impact of crisis situations on the socio-economic status of the region and assessing the degree of their impact.Conclusion. Based on the results of the analysis, recommendations were given for the development of the region, which can be used in the implementation of socio-economic policy. Particular attention is paid to indexes of living standards.

Agroindastrial complex of the Chuvash Republic: intra-regional and All-Russian significance

This paper reveals the current state of various areas of the agro-industrial complex of the Russian region of the Chuvash Republic. Particular attention was paid to comparing a number of parameters characterizing the agro-industrial production of the republic with the corresponding parameters of other areas of the economy of the region, the role of the agro-industrial complex of Chuvashia in the all-Russian agro-industrial production. In the Chuvash Republic, the importance of the agro-industrial complex for the regional economy is often emphasized. Moreover, in the typology of Russian regions in terms of the level and type of economic development, the Chuvash Republic is quite often referred to the category of agro-industrial regions. The paper describes the absence of exceptional natural and climatic advantages for the development of the agro-industrial complex of the region, the relative weakness of the agricultural and agro-industrial sectors of the republic against the background of a number of other regions of Russia. The share of the industry in the structure of GRP and employment in the region is analyzed, while its importance is highlighted against the background of manufacturing industries and the service sector. It also stands out that the modern agro-industrial complex of the Chuvash Republic is of great importance for the socio-economic development of the region and the prospects for further development. However, it is not possible to classify Chuvashia as an agrarian and even agro-industrial region. The most important in the republic is not the agro-industrial complex, but the social infrastructure, industrial infrastructure and industry.

Non-Linearity of Thermosetting Polymers' and GRPs' Thermal Expanding: Experimental Study and Modeling.

Thermal expanding is the important property that defines the stress–strain condition of GRP structures exploited under heating and having limited thermal resistance. So, the GRPs’ thermal expanding prediction is the actual requirement of such structures design. The experimental accurate dilatometric study resulted in the non-linearity of thermosetting polymers and plastics thermal expanding under heating. The polymers and plastics thermal expanding coefficient (CTE) is non-linearly increasing under heating before glassing temperature (Tg). Using the previous polymers and GRPs modelling experience and experimental dilatometric results, the non-linear adequate prediction models of their CTE were proposed and proved. The new compensative wave model of polymers’ CTE and multi-layer model of GRPs’ CTE were proposed and successfully tested. A prediction of the temperature dependences of the thermal expansion coefficients of various thermoset polymer binders and data on the reinforcement structure was performed based on the experimentally obtained temperature dependences of the CTEs of GRPs. The prediction was performed using the finite-element homogenization method in the Material Designer module of the academic version of the Ansys package. A satisfactory concurrence of the numerical results of the prognosis and the experiment for all considered cases is observed in the temperature range from 50 to 100 °C, after glass transition temperature best coincidence of numerical values of CTE is obtained for glass-reinforced plastics on epoxy resin, which were not subjected to thermal aging.

РЕГИОНАЛЬНОЕ НЕРАВЕНСТВО В СОЦИАЛЬНО-ЭКОНОМИЧЕСКОМ РАЗВИТИИ РОССИИ

The topic of regional inequality in socio-economic development is becoming more relevant every year. Ensuring the uniform development of the Russian regions is complicated by the high degree of heterogeneity of the country's economic space, which is expressed in socio-economic inequality between the regions. Currently, there is a differentiation of the subjects of the Russian Federation by the sectoral structure of GRP, by the level and quality of life of the population, etc., there are imbalances in budget security. This leads to a decrease in the attractiveness and competitiveness of the regions and generally weakens the national economy. According to the World Bank, Russia ranks 3rd in the world in terms of regional inequality. Government documents indicate that the state's goal is to reduce the differentiation of socio-economic development in regions with a reduced standard of living by 2022. The spatial development of most economic entities is characterized by significant differences. Economists point out that interregional asymmetryarises due to competitive advantages and features of the institutional environment. Reducing the inequality of regional development is possible if the standard of living in the depressed regions of the Russian Federation is increased. An important area for assessing the differentiation of regions is the development of a system of indicators that assess regional inequality. The assessment of the role of the region in the production of GRP can be obtained by calculating localization indicators and relative position indices, the dynamics, variation and depth of regional inequality are characterized by dispersion coefficients, as well as the differentiation of the population of regions by income, the analysis of the uniformity of the distribution of regions can be obtained from the analysis of income concentration indicators. In general, it can be noted that regional inequality in the socio-economic development of Russia tends to increase.

Substantiation of strategic directions and structural results of reforming the economy of Ukraine

The strategic directions of reforming the economy of Ukraine are analyzed. The author defines the main reasons for the existence of structural imbalances, including limited resources (material, intellectual, financial, investment, innovative); reduction of innovative production; high material and energy intensity of production; a high share of intermediate structure of GRP, which shows a limited production of goods and services with a high share of GVA; low development of innovation infrastructure. The paper proves that the real sector of the economy is in a state of deindustrialization and needs to restore technological, scientific, intellectual, and export capacity. As a result, the author has focused attention on the necessity of systemic reforms in a number of areas, which should become the basis for the dynamic socially-oriented development of Ukraine. The most important reforms include the technological modernization, reindustrialization, increase of high-tech exports, systemic de-shadowing and formation of a competitive environment, business development, expansion of the middle class, modernization of social security and investment attractiveness, development of strategic industries, domestic market development, resource sector growth, and energy efficiency. The structural results of reforming the economy of Ukraine are summarized and indicators that will represent the efficiency of changes in each of the reformed basic areas are identified. For example, the efficiency of the reforms implementation in the social sphere will be displayed by the growth of incomes and the level of life quality and well-being of the population. In the field of education, such results will be summarized by increasing the quality and competitiveness of education, its harmonization with the needs and demands of professionals in the labor market. In the field of healthcare, the changes will be displayed in the creation of a modern reformed health care system with a high level of quality and accessibility of medical services. The decrease of migration activity processes is defined as the main result of the development of the internal labor market.

Statistical analysis of the driving forces of anthropogenic impact on the environment

The aim of the study is to analyze the driving forces of the impact of human activities on the environment. The problem of assessing the influence of the population size, the level of economic development, as well as the technological factor on the volume of emissions of pollutants into the atmospheric air in the regions of the Russian Federation is considered. A retrospective of models for analyzing the main driving forces of anthropogenic impact on the environment is presented. The study is based on the STIRPAT model. The results of the econometric assessment showed that both the population and the level of economic development (GRP per capita) have a decisive influence on the increase in air emissions in the regions of the Russian Federation. A decrease in the energy intensity of GRP, as well as the share of manufacturing and extractive industries in the sectoral structure of GRP, also leads to a significant decrease in the environmental load. However, the values of the corresponding environmental elasticities are significantly lower than the elasticities of emissions of pollutants into the atmosphere with changes in population size and economic growth (GRP per capita).

The Specialization of the Russian Economy: Regional Aspect

Modern trends of production of gross regional product in Russia are analyzed in this paper. Regional and industrial structure of GRP is investigated. The conditional classifications, interregional differentiation of constituent members of the Russian Federation are indicated by means of efficiency factors and the dynamics of real production of gross value added.The scientific novelty of this research is concluded in the analysis algorithm offered by authors and the choice of indicators for the scales’ characteristic and intensity of economic processes at the level of regions in modern conditions. The scientific problem solved in a research consists not only in the review of a modern situation, but also allows to reveal features of efficiency and real production dynamics of gross value added in members of the country for the purpose of perspective directions’ identification of the balanced development of the national economy.The theoretical and practical significance of the research consists in a possibility of usage of the result for the verification of perspective directions of national economy development and in the main methods and instruments justification for the formation of industrial state policy.

Сравнительная оценка динамики эффективности инвестиций в основной капитал на уровне федеральных округов России

The article proposes an approach to the determination of investment efficiency at the regional level and provides a comparative assessment of investment efficiency in different economic activities.The assessment of investment efficiency is preceded by the analysis of GRP structures and investments in the economy of the Central Federal District in the context of foreign trade, which allows to identify and then to give a comparative assessment of investment efficiency in fixed capital in the two leading types of economic activities on the share of GRP in the Central Federal District in 2005 and 2012: trade and processing production.The instruments for analysis became a package of statistical programs SPSS Statistics 22.

Postindustrial transformations of Russia’s regional economies

The article studies the major tendencies in the structural transformations of Russia’s regional economies with an emphasis on postindustrial changes. A comparison of the tendencies in postindustrial transformation in Russia and several other countries has been made. The interregional differences in the employment patterns and GRP structure in 2008–2010, as well as the differences in the directions and transformation rates of the employment patterns and GRP structures of Russian regions (with an emphasis on the tertiary sector’s role), have been analyzed. The role of market and nonmarket services in the process of postindustrial transformation of Russia’s regional economies has been examined. The phenomena of “false tertiarization” and “false reindustrialization” have been studied.

Application of Gradient Based IR Thermography to the GRP Structures Inspection

The article presents application of non destructive testing method based on the pulse heating infrared thermography used to detect material anomalies for the case of glass reinforced polymer structures. The goal of presented research, based on the thermal gradient approach, is to establish the procedure capable of filtering out anomalies from other thermal influences caused by thermal reflections of surrounding objects, geometry influences and heat flows for observed object.

The Effects of Seawater Environment, Material Direction and Thickness on the Fatigue Performance of Adhesively Bonded and Bolted Joints of Non-Crimp GRP Structures

In this experimental study, which was undertaken to evaluate the combined effects of material direction, thickness and seawater environment on the fatigue behaviour of adhesively bonded and bolted joints widely used in GRP boat building, the specimens, which were produced by composite system, which its matrix material was multi-purpose polyester (Dewester 196 from the Dewilux Inc.) and its reinforcing material was non-crimp, E-glass fibres, has been used. Unjoined control specimens taken from two different panels (thickness of 5 mm and 11 mm) with the direction of 0′I, were subjected to the tests carried out under both atmospheric and marine conditions, together with unjoined with the directions of 45′I and 90′I, bonded and bolted specimens taken from the same panels. The study was started with static tensile tests of unjoined and jointed specimens, which have two different thickness, 5 mm and 11 mm and have been aged in 3.5% of NaCl solution, which represents seawater environment, and the results obtained give suggestions on tensile values, which would be used in tension-tension fatigue tests. The cycling in tension-tension fatigue tests was between tensile maximum and zero stress value and the frequency value applied was 7.5 Hz. The specimens, which were subjected to tests in synthetic seawater environment, had been aged previously. The results occurred depending on the material direction, the thickness and the joining type of the material are given in conclusion by comparison. It was seen that the results obtained by testing the material in synthetic seawater is much lower than the results of obtained from testing similar specimens under atmospheric conditions. However, the cyclic stress curves indicate the same slope, suggesting that the fatigue failure mechanism of both testing conditions is the same and the fibre-related factors dominate.

Thermal and structural performance of GRP panels and short columns under fire conditions

This paper presents the results of an experimental study of the behaviour of different types of GRP structures under fire conditions. The experiments were conducted in two stages. The first part is concerned with the thermal performance of GRP sandwich panels and stringer systems when exposed to fire on one side. The objective of this study is to provide experimental information of temperature developments in GRP structures in fire. The products examined in this investigation include: glass reinforced phenolic laminate sheets, lightweight phenolic foams, sandwich panels made from GRP sheets and phenolic foams, sandwich panels made from plasterboards and phenolic foams, stringer systems made from GRP sheets and pultruded GRP channels insulated with mineral wool and stringer systems made from plaster boards and pultruded GRP channels with mineral wool. For comparison, fire tests were also carried out on conventional steel stud systems consisting of plasterboards and cold-formed-thin-walled steel channel sections insulated with mineral wool. In all these tests, the core materials were 100 mm thick. Plasterboards were 12.5 mm thick and the GRP sheets were 3 mm thick. Fire exposure was according to the standard BS: 476 Part 20 – Cellulosic fire temperature–time relationship. The second part gives results of compressive tests on pultruded short GRP channel sections at elevated temperatures to evaluate their residual strength in fire. The objectives of these tests are to assess the feasibility of using GRP based products as wall construction in low storey buildings such as accommodation units and also to provide experimental data for the calibration of numerical models of heat transfer and structural analysis. Results of these tests indicate that the low-density phenolic foam used in this study was involved in burning very early in the fire test and would not be suitable for fire resistant construction. Initially the fire exposed thin GRP sheet could not provide as much insulation as the plasterboard, however, the GRP sheet prevented direct heating of the core material and was able to reduce the core material temperatures considerably. At 30 min of the standard fire exposure, temperatures in large parts of the GRP stringer systems were less than 100 C. For compressive tests, pultruded channel sections 100 x 30 x 4 mm by 400 mm long were heated in an electric kiln furnace to different levels of temperature and then loaded to failure in compression in a specially constructed loading facility. The test temperatures were 20, 60, 90, 120, 150, 200 and 250°C. The results of these tests indicate that GRP materials lose their strength and stiffness at relatively low temperatures, however, due to their low thermal conductivity, temperatures in large parts of the pultruded GRP channel sections were very low (less than 100°C) enabling them to carry some loads (up to 70%) under fire conditions.

Residual stresses arising from partial in-service post-cure of GRP structures

Abstract Strain gauge measurements on glass fibre-reinforced plastic ( grp ) specimens subjected to elevated temperatures indicated that shrinkage associated with post-curing is such that, should it be restrained in any way, stresses of reasonable magnitude can be developed. Laboratory tests on a thick-walled grp tube and field tests on a grp thermosiphon evaporator showed that such restraint can be developed by partial post-curing of the material due to the temperature gradients developed in service. Under these conditions residual tensile stresses are developed on the laminate side subjected to the elevated temperature and, most probably, the chemical environment. With environmentally assisted cracking being sensitive to tensile stress level, it is likely that the residual tensile stresses can contribute to the premature failure of equipment not subjected to a full post-cure prior to commissioning.

Core material for GRP structures

Core material for GRP structures

A study of the effect of natural weathering on the creep behaviour of glass fibre-reinforced polyester laminates

Glass fibre-reinforced polyester laminates having different compositions, typical of those used in commercial building panels were exposed to natural weathering at stress levels varying between 7 and 35% of the composites' short-term flexural strength. The creep curves show considerable dependence of the creep rate and the deformation on weathering. Increase in the percent strain for all nine types of laminates subjected to study has been observed to be less than 1% in 15 000 hours of exposure. The trends shown by this work indicate that grp structures may be suitable for outside use provided that good quality laminates are used.