Thin-Walled Composite and Plastic Shells for Civil and Industrial Buildings and Erections

2017 ◽  
Vol 895 ◽  
pp. 45-51 ◽  
Author(s):  
Sergey Nikolayevich Krivoshapko ◽  
Svetlana Lvovna Shambina ◽  
Christian A. Bock Hyeng
Keyword(s):  
Composite Structures ◽  
Shell Structures ◽  
Thin Shells ◽  
Synthetic Resin ◽  
Reinforced Plastics ◽  
Industrial Buildings ◽  
Positive Gaussian Curvature ◽  
The Usa ◽  
The Subject ◽  
Thin Walled

Commercial production of synthetic resin has begun at the beginning of the XX century. In 1950s in the USA, small-span dome roofs, scanner assemblies and spherical hangars for radars made of plastic began to appear. Later, invention of reinforced plastics gave a possibility to use them in thin-walled shells for civil and industrial buildings. The subject of the paper associates with today’s renewed interest in thin shells. The modern theoretical base of strength analyses of composite structures give a possibility to design different structures and buildings. The possibility of the application of composites as the basic elements of thin-walled shell structures of industrial and civil purpose are illustrated by the concrete examples. The paper presents information on the well-known composite shells of positive Gaussian curvature in the form of spherical and umbrella domes or with more complex middle surfaces and presents materials that are absent in other publications. The paper contains 9 figures and 15 references.

RESERVE OF ANALYTICAL SURFACES FOR ARCHITECTURE AND CONSTRUCTION

2021 ◽  
Vol 98 (6) ◽  
pp. 63-72
Author(s):  
GIL-OULBE MATHIEU ◽  
Keyword(s):  
Mechanical Engineering ◽  
Building Materials ◽  
Shell Structures ◽  
Housing Construction ◽  
Spatial Structures ◽  
Surfaces Of Revolution ◽  
Industrial Buildings ◽  
New Ideas ◽  
Wavy Surfaces ◽  
Thin Walled

After a period of relative calm in the construction and design of thin-walled large-span shells and network multilayer shell structures, which, according to the world's leading architects, began in the 1980 s, the time has come for the expanded use of spatial structures in the architecture of public and industrial buildings. Less commonly, shells are used in small-sized housing construction: ecological villages, noospheric and bionic architecture. The entire 20th century did not stop research on the development of analytical and numerical methods for analyzing shells for strength and stability, for the creation of new building materials. Geometers have created and studied more than 600 analytical surfaces that can be mistaken for the mid-surfaces of civil and mechanical engineering shells. As a result, by the beginning of the 21st century, architects and engineers had all the necessary tools to continue the traditions of the "golden age of shells". The analysis of problems with the use of new forms in parametric architecture, carried out in the article, showed that more than ten classes of surfaces from their classification have not yet found application in architecture and mechanical engineering. It is assumed that the number of applied classes of surfaces will not expand, and new ideas for the shaping of shells will be based on the use of already well-known surfaces, namely, surfaces of revolution, transfer, umbrella, minimal, ruled and wavy surfaces. Mainly, shell structures will be designed taking into account environmental, energy-saving requirements and transforming structures.

Non-Destructive Testing of Thermoplastic Carbon Composite Structures

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański
Keyword(s):  
Composite Structures ◽  
Ultrasonic Method ◽  
Composite Panel ◽  
Aviation Industry ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulse Technique ◽  
Thermoplastic Matrix ◽  
The Subject ◽  
Non Destructive

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.

The Israeli–Lebanese war of 2006: consequences for Lebanon

2008 ◽  
Vol 1 (2) ◽  
pp. 187-210
Author(s):  
Ziad Hafez
Keyword(s):  
Arab Countries ◽  
The Political ◽  
National Unity ◽  
Major Consequence ◽  
Political Narrative ◽  
Defence Policy ◽  
Before And After ◽  
The Usa ◽  
The Subject ◽  
The Impact

This article focuses on the political narrative in Lebanon before and after the Israeli war against Lebanon in 2006. It revolves around the subject of national unity as a sine qua non condition for success for the Lebanese resistance led by Hezbollah. A major consequence of the narrative on national unity is the need to build a modern state and establish a cohesive defence policy. The paper also examines the impact of the war on Lebanon's economy and on its relations with the rest of the world (the USA, France, Syria, Arab countries, and Iran).

Progressive failure analysis of thin-walled composite structures

2013 ◽  
Vol 95 ◽  
pp. 53-62 ◽  
Author(s):  
Diego Cárdenas ◽  
Hugo Elizalde ◽  
Piergiovanni Marzocca ◽  
Frank Abdi ◽  
Levon Minnetyan ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Composite Structures ◽  
Progressive Failure ◽  
Progressive Failure Analysis ◽  
Thin Walled

PROVIDING FREE LEGAL ASSISTANCE TO PERSONS SENTENCED TO IMPRISONMENT IN RUSSIA AND THE USA: A COMPARATIVE ANALYSIS

2021 ◽  
pp. 14-19
Author(s):  
Оксана Алексеевна Владимирова
Keyword(s):  
United States ◽  
Comparative Analysis ◽  
The United States ◽  
Synthesis Methods ◽  
Legal Assistance ◽  
American System ◽  
The Usa ◽  
Legal Foundations ◽  
The Subject ◽  
Domestic Practice

Статья посвящена исследованию опыта оказания бесплатной юридической помощи осужденным к лишению свободы в США, а также проведению сравнительного анализа данного и отечественного опыта. Целью работы является изучение основных организационных аспектов и правовых основ оказания юридической помощи такой категории граждан, как осужденные, с целью установления закономерностей и выявления возможности использования положительных аспектов указанного опыта в российском законодательстве. Методы, использующиеся при написании статьи: диалектический, анализ, синтез, сравнительно-правовой. В статье последовательно изучается организация оказания бесплатной юридической помощи осужденным и их родственникам в различных регионах (штатах) США. Особое внимание уделяется субъектам оказания помощи, а также специфике отдельных механизмов и особенностей работы организаций по оказанию безвозмездной помощи осужденным. В качестве особенности американской системы оказания правовой помощи автор особенно выделяет предметный (специализированный) подход к вопросам оказания помощи - отдельные организации занимаются оказанием помощи по выбранному узкому кругу вопросов. Исследование российского опыта правовой помощи осужденным позволяет отметить некоторые преимущества. Вместе с тем, анализ проблем, существующих в системе оказания бесплатной юридической помощи осужденным к лишению свободы, позволил сделать вывод о необходимости совершенствования системы юридической помощи в России. В результате работы выявлен положительный опыт, возможный для применения в российском законодательстве. The article is devoted to the study of the experience of providing free legal assistance to those sentenced to imprisonment in the United States, as well as to the comparative analysis of this experience and that available in domestic practice. The purpose of this work is to study the main organizational aspects and legal foundations of providing legal assistance to such a category of citizens as convicts in order to establish patterns and identify the possibility of using the positive aspects of this experience in Russian legislation. Methods used in this study: dialectical method of cognition, analysis, synthesis, methods of comparative law. The article consistently examines the organization of the provision of free legal assistance to convicts and their relatives in various regions (states) of the United States. Great attention is paid to the subjects of assistance, as well as the specifics of individual mechanisms and features of the work of organizations to provide gratuitous assistance to convicts. As a feature of the American system of providing legal assistance, the author especially highlights the subject (specialized) approach to assistance issues - individual organizations are involved in providing assistance on a selected narrow range of issues. The study of the Russian experience of legal assistance to convicts reveals some advantages. At the same time, the analysis of the problems existing in the system of providing free legal assistance to those sentenced to imprisonment made it possible to conclude that it is necessary to improve the system of legal assistance in Russia. As a result of the work, a positive experience was revealed that could be applied in Russian legislation.

Buckling Analysis of Carbon Fiber Reinforced Plastics Cylinders under Axial Compression

2013 ◽  
Vol 395-396 ◽  
pp. 76-79
Author(s):  
Da Huang ◽  
Cheng Hong Duan
Keyword(s):  
Carbon Fiber ◽  
Axial Compression ◽  
Composite Structures ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
The Stability

In this paper, the stability of carbon fiber reinforced plastics (CFRP) cylinders under axial compression was studied by the finite element analysis method. According to the Riks method, compressive capacity of the composite structures was investigated by nonlinear analysis, in which the eigen buckling modes were considered in the form of initial defects. And the post-buckling performances of different structures were also compared.

scholarly journals Estimating evapotranspiration using the complementary relationship and the Budyko framework

2017 ◽  
Vol 8 (4) ◽  
pp. 771-790 ◽  
Author(s):  
Homin Kim ◽  
Jagath J. Kaluarachchi
Keyword(s):  
Root Mean Square Error ◽  
Vegetation Cover ◽  
Meteorological Data ◽  
Mean Square ◽  
Limited Data ◽  
Complementary Relationship ◽  
Proposed Model ◽  
The Usa ◽  
Dry Conditions ◽  
The Subject

Abstract Several models have been developed to estimate evapotranspiration. Among those, the complementary relationship has been the subject of many recent studies because it relies on meteorological data only. Recently, the modified Granger and Gray (GG) model showed its applicability across 34 diverse global sites. While the modified GG model showed better performances compared to the recently published studies, it can be improved for dry conditions and the relative evaporation parameter in the original GG model needs to be further investigated. This parameter was empirically derived from limited data from wet environments in Canada – a possible reason for decreasing performance with dry conditions. This study proposed a refined GG model to overcome the limitation using the Budyko framework and vegetation cover to describe relative evaporation. This study used 75 eddy covariance sites in the USA from AmeriFlux, representing 36 dry and 39 wet sites. The proposed model produced better results with decreasing monthly mean root mean square error of about 30% for dry sites and 15% for wet sites compared to the modified GG model. The proposed model in this study maintains the characteristics of the Budyko framework and the complementary relationship and produced improved evapotranspiration estimates under dry conditions.

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