scholarly journals Columnas Compuestas de Hormigón y Acero SRC, Sujetas a Flexocompresión Biaxial

2018 ◽  
Vol 3 (1) ◽  
pp. 281
Author(s):  
Jorge Ricardo Vintimilla Jaramillo ◽  
Luis Tinerfe Hernández Rodríguez

The work presented is based on experimental and theoretical analysis of SRC composite columns subjected to biaxial bending and axial compression, where the specification of American and European code criteria are used to calculate de load bending strength. The computer program to calculate the interaction diagram of biaxial bending and axial compression with inclined neutral axis is made in the software Matlab by using the fiber method, besides, the strength of the specimen is calculated. Users can design new frame sections and check the exist sections. To obtain the displacements and load curve, to calculate load contours and determination of the interaction family curves of the modeled sections. The destructive performance of the round and rectangle composite columns are made in the structures laboratory of EPN to obtain the results such as the buckling displacement at strong, weak and longitudinal direction measured with LVDT´S. Subsequently, the theoretical and experimental analysis results are made to demonstrate the reliability of the numeric model.Keywords: Composite Columns, Concrete, Steel

2018 ◽  
Vol 7 (2.23) ◽  
pp. 99 ◽  
Author(s):  
M A. Othuman Mydin ◽  
N Mohamad ◽  
I Johari ◽  
A A. Abdul Samad

This paper focuses on laboratory investigation to scrutinize and portray the Young’s modulus of cellular mortar exposed to high temperatures. Two densities of cellular mortar of 600 and 900 kg/m3 density were cast and tested under axial compression and 3-point bending. The tests were performed at room temperature, 105°C, 205°C, 305°C, 405°C, 505°C, and 605°C. The results of this study consistently indicated that the loss in toughness for cement based material like cellular mortar exposed to high temperatures happens principally after 105°C, irrespective of density of cellular mortar. This specifies that the principal contrivance instigating stiffness deprivation is micro cracking in the cement matrix, which happens as water magnifies and disappears from the porous body. As projected, decreasing the density of cellular mortar diminishes its compressive strength and bending strength. Though, for cellular mortar of different densities, the normalized strength-temperature and Young’s modulus-temperature relationships are comparable.  


Author(s):  
Stuart McKernan

For many years the concept of quantitative diffraction contrast experiments might have consisted of the determination of dislocation Burgers vectors using a g.b = 0 criterion from several different 2-beam images. Since the advent of the personal computer revolution, the available computing power for performing image-processing and image-simulation calculations is enormous and ubiquitous. Several programs now exist to perform simulations of diffraction contrast images using various approximations. The most common approximations are the use of only 2-beams or a single systematic row to calculate the image contrast, or calculating the image using a column approximation. The increasing amount of literature showing comparisons of experimental and simulated images shows that it is possible to obtain very close agreement between the two images; although the choice of parameters used, and the assumptions made, in performing the calculation must be properly dealt with. The simulation of the images of defects in materials has, in many cases, therefore become a tractable problem.


2019 ◽  
Vol 10 (5) ◽  
pp. 473-478
Author(s):  
Ahmad Gashamoglu ◽  

The Article briefly discusses the need for generation of the Science of Ahangyol, and this science’s scientific basis, object and subject, category system, scientific research methods and application options. Ahangyol is a universal science and may be useful in any sphere. It may assist in problem solving in peacemaking process and in many areas such as ecology, economics, politics, culture, management and etc. This science stipulates that any activity and any decision made in the life may only and solely be successful when they comply with harmony principles more, which are the principles of existence and activity of the world. A right strategic approach of the Eastern Philosophy and the Middle Age Islamic Philosophy and scientific thought has an important potential. This strategic approach creates opportunities to also consider irrational factors in addition to rational ones comprehensively in scientific researches. The modern scientific thought contributes to implementation of these opportunities. Ahangyol is a science of determination of ways to achieve harmony in any sphere and of creation of special methods to make progress in these ways through assistance of the modern science. Methods of the System Theory, Mathematics, IT, Astronomy, Physics, Biology, Sociology, Statistics and etc. are more extensively applied. Information is given on some of these methods. Moreover, the Science of Ahangyol, which is a new philosophical worldview and a new paradigm contributes to clarification of metaphysic views considerably and discovery of the scientific potential of religious books.


2021 ◽  
Vol 10 (4) ◽  
pp. 196
Author(s):  
Julio Manuel de Luis-Ruiz ◽  
Benito Ramiro Salas-Menocal ◽  
Gema Fernández-Maroto ◽  
Rubén Pérez-Álvarez ◽  
Raúl Pereda-García

The quality of human life is linked to the exploitation of mining resources. The Exploitability Index (EI) assesses the actual possibilities to enable a mine according to several factors. The environment is one of the most constraining ones, but its analysis is made in a shallow way. This research is focused on its determination, according to a new preliminary methodology that sets the main components of the environmental impact related to the development of an exploitation of industrial minerals and its weighting according to the Analytic Hierarchy Process (AHP). It is applied to the case of the ophitic outcrops in Cantabria (Spain). Twelve components are proposed and weighted with the AHP and an algorithm that allows for assigning a normalized value for the environmental factor to each deposit. Geographic Information Systems (GISs) are applied, allowing us to map a large number of components of the environmental factors. This provides a much more accurate estimation of the environmental factor, with respect to reality, and improves the traditional methodology in a substantial way. It can be established as a methodology for mining spaces planning, but it is suitable for other contexts, and it raises developing the environmental analysis before selecting the outcrop to be exploited.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.


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