Comparative Analysis of Plasticity Theory Algorithms in Finite-Element Calculations of the Rotation Shell

2019 ◽  
Vol 974 ◽  
pp. 608-613
Author(s):  
Yuriy V. Klochkov ◽  
Anatoliy P. Nikolaev ◽  
Tatiana A. Sobolesvskaya ◽  
Mikhail Yu. Klochkov

Comparative analysis of the use of the defining equations of plasticity theories obtained at the loading step in three ways is performed. In the first method, the relations between strains increments and stresses increments are obtained by differentiating the governing equations of the small elastic-plastic deformations theory between full stresses and strains. In the second method, the authors based on the proportionality hypothesis between the component deviators of strains increments and the component deviators of stresses increments without separating the incremental strain into elastic and plastic parts obtain the determining equations at the loading step. In the third method, the relations between the incremental strain and the stresses increment of the plastic flow theory are used on the basis of the hypothesis about the proportionality of the plastic deformations increments to the components of the stress deviator. Based on the analysis of algorithms for obtaining the constitutive relations and the analysis of the numerical results of the calculation example, preference is given to the second method of obtaining expressions between stress increments and strain increments without separating the latter into elastic and plastic parts.

2018 ◽  
Vol 28 (3) ◽  
pp. 991-996
Author(s):  
Gabriela Kirova

Starting with 2018/2019 school year in Bulgaria, the math education in the third grade is implemented through new training kits. They were developed on the basis of the new third-grade mathematics curriculum, approved by Order No. РД 09-1093 / 25.01.2017 of the Minister of Education and Science, Annex No. 8, supplemented by Order No. РД 09-2555 / 15.06.2018 of the Minister of Education and Science. Training kits are approved by the Ministry of Education and Science and are 7 in total. Geometric learning content in new math textbooks is the second most important element after arithmetic content. It is combined with the arithmetic learning content, and by this the foundation of the successful study of geometry in the next school grades is laid. The new geometry knowledge that is included in the third grade curriculum is the following: straight line, curve, beam, angle, right angle, obtuse angle, acute angle, right triangle, acute triangle, obtuse triangle; naming geometric figures with Latin alphabet letters [11]78. It is important in a modern mathematics textbook to have a rich and varied geometric content. It is important that the new types of geometry tasks are introduced with rich visualization using a specific-inductive approach. The relative number of tasks of a given type is an important prerequisite for the successful formation and improvement of skills for solving geometric problems in pupils at the age of 9-10. This article will present a comparative analysis of the geometric content in the seven approved Bulgarian third-grade mathematics textbooks, which are used in the mass practice of this school year. For the purpose of the study, a classification of all types of tasks and exercises with geometric content has been developed. Then the tasks in the seven textbooks are systematized by the so chosen classification. The data are statistically processed taking into account the relative share of tasks of each type within a textbook, as well as a comparison between the relative shares of the geometric tasks in the different textbooks. The established differences in the number and relative share of different types of geometric tasks make it possible for the analyzed textbooks to be ranked. Such a study has not been published so far. It has a relation to the assessment of the quality of the textbooks offered. The conclusions formulated in this article can help primary teachers in their choice of textbooks to teach to their third grade students.


1990 ◽  
Vol 57 (4) ◽  
pp. 1088-1091 ◽  
Author(s):  
G. Jemielita

The paper presents a survey of the kinematical hypotheses and the governing equations of the refined theories of plates. By carrying out a comparative analysis of various, apparently different, kinematical hypotheses proposed by various authors, it is shown that the kinematical hypothesis by Vlasov (1957) is a pattern for all of them.


2018 ◽  
Vol 72 (1) ◽  
pp. 41-70
Author(s):  
Dragoş Andrei Giulea

Abstract A comparative analysis of Ep. 361 and Eun. 1.19 in terms of language and ideas will offer a renewed confirmation (on internal grounds) of Basil of Caesarea’s authorship of Ep. 361 and a new perspective on Basil’s relationship with the Homoiousians. In addition, the article will also retrace the steps and revisit the purpose of Basil’s argument. Thus we discover in the early Basil an author simultaneously receptive to both Homoiousian and pro-Nicene visions, but leaning towards an improved Homoiousian solution. The article further investigates Basil’s vision of ousia in Ep. 361 and finds that—unlike in his later, mature, period—the early Basil shares with the Homoiousians and Eusebius of Caesarea two doctrinal elements, namely the understanding of ousia as individual substance and an associated theology of “likeness”. He inherits this view from a tradition originating in the third century, which received its official confirmation at the council of Antioch in 268. This vision is also present in the first part of Basil’s Contra Eunomium. Instead of considering Basil as a Homoiousian, one may see him, together with Eusebius and the Homoiousians, as a representative of the Antiochene legacy.


2019 ◽  
Vol 6 (1) ◽  
pp. 15-22
Author(s):  
Mahmoud Fard Kardel

The main purpose of this article is to examine Iran’s legal and contractual framework for their petroleum, oil and gas industry. Basically, the legal and contractual framework of the Iranian oil and gas industry has been classified into three periods. The first period is from the exploration and discovery of oil in Iran to nationalisation (1901-1951), the second period is from nationalisation to revolution (1951-1979), and the third period is from revolution to the present day (1979-20016).Because each period has its own features and importance two articles will examine this topic. The first period (from exploration to nationalisation, 1901-1951), and second period (from nationalisation to revolution, 1951-1979), has been examined in this article with legal and comparative analysis, and the third period (1979-2016) will be covered in a later article.It should be mentioned that each contractual framework was a turning point regarding to opportunities and circumstances that they have been in that time and also each of those petroleum contractual regimes were a step toward to contractual framework evolution in Iran.


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