Wyniki wyszukiwania - BazTech

1

The effect of the Kenaf natural fiber on enhancing the mechanical properties of bio-composites materials used in civil engineering

Bouguenina O., Mokaddem A., Doumi B., Berber M., Boutaous A.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 1

301--311

EN

In this work, we have investigated the effect of the natural Kenaf reinforcement on the improvement of the interfacile bond between two types of epoxy and Polypropylene (PP) matrix. Our genetic model is based on Weibull’s probabilistic models and on Cox’s interface model. The moisture content for each material is determined by Fick’s law. Our simulation results show that the most resistant interface is that of Kenaf-Polypropylene compared to the other interfaces. This result coincides perfectly with the experimental data found by Paul Wambua et al. Which have shown that Kenaf is a promoter fiber for the improvement of the mechanical properties of biocomposite used in the field of civil engineering.

2

Study and localization by the nonlinear acoustic technique of the damage to the fiber-matrix interface of a bio-composite

Attemane A., Mokaddem A., Doumi B., Boutaleb M., Temimi L., Boutaous A.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 3

453--465

EN

The objective of this paper is to study the effect of dissipated energy on the damage to the fiber-matrix interface of a Hemp/Pla bio-composite, localized by the non-linear acoustic technique. For this purpose, we used the model defining energy dissipation during a charge/discharge cycle in our numerical simulation based on the Weibull probabilistic model and Cox model. We found that the energy dissipated is directly related to the damage; and when the damage increases the dissipated energy increases rapidly in the first cycles (1, 2,3 and 4) and very quickly for the last charge/discharge cycles (5,6 and 7). We concluded that the energy dissipated showed the state of degradation of Biocomposite prior to its start-up, and that the non-linear acoustic technique also indicates and confirms the same results found.

3

Investigation and simulation by a metaheuristic algorithm of the effect of carbon nanotubes fibers on the improvement of the properties of nanocomposite material

Oukkas M., Mokaddem A., Doumi B., Boutaleb M., Temimi L., Boutaous A.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 4

1009--1020

EN

In this article, we investigated and studied the effect of carbon Nanotubes fibers on the improvement of the mechanical and thermal properties of our epoxy matrix composite material. Our calculations were based on a heuristic optimization algorithm. The results show that the level of the damage is related to the concentration of the mechanical and thermal stresses, for the three materials studied carbon/epoxy, Graphite-epoxy and carbon nanotubes/epoxy, the calculations also show that carbon nanotubes have greatly improved the mechanical and physical properties of our material, and that this material is more resistant than the other carbon/epoxy composite materials and graphite-epoxy nanocomposite. The numerical simulation shows a good agreement with the real behavior of the three materials studied. This means that the mechanical and physical properties have been greatly improved after the use of carbon nanotubes fibers. Finally, we can say that our model has worked well in relation to the phenomenon of damage of composites and nanocomposites materials. It would be interesting to see, thereafter, the effect of carbon nanotubes fibers on the damage of the fiber-matrix interface of a bio-nanocomposite.

4

Study by Genetic Algorithm of the Role of Alfa Natural Fibre in Enhancing the Mechanical Properties of Composite Materials Based on Epoxy Matrix

Ziani N., Boudali A., Mokaddem A., Doumi B., Beldjoudi N., Boutaous A.

Fibres & Textiles in Eastern Europe

|

2016

|

Vol. 24, no. 3 (117)

58--62

EN

Natural fibres have a very important role in improving the mechanical properties of composite materials. Our objective in this study was to use alfa natural fibre in a composite material based essentially on epoxy matrix and calculate the interface fibre-matrix damage of carbon-epoxy, glass-epoxy and alfa-epoxy. Each sample was reinforced with the same volume fraction before being subjected to various mechanical tests. The results found by genetic simulation showed that the level of damage to the alfa-epoxy material was lower compared to other composite materials studied. We can say that alfa natural fibre has a high resistance to the mechanical stress applied; but the question remains whether the new material has the same resistance to thermal stress.

PL

Włókna naturalne spełniają bardzo ważną rolę przy polepszeniu właściwości mechanicznych materiałów kompozytowych. Celem badań w przedstawionej pracy było zastosowanie naturalnych włókien alfa dla wzmocnienia mechanicznych właściwości materiałów kompozytowych z matrycą epoksydową. Określano zniszczenie międzyfazowych układów włókna węglowe-epoksyd, włókna szklane-epoksyd i włókna alfa-epoksyd. Każda badana próbka była wzmacniana tym samym objętościowym udziałem poszczególnych rodzajów włókien. Wyniki badań określone przy stosowaniu symulacji genetycznej pokazały, że poziom zniszczenia układów fazowych alfa-matryca epoksydowa był niższy w porównaniu do innych badanych materiałów kompozytowych. Na podstawie przeprowadzonych badań można stwierdzić, że naturalne włókna alfa posiadają wysoką odporność na przyłożone naprężenia mechaniczne. Zagadnieniem nierozwiązanym pozostaje czy włókna naturalne alfa posiadają dobrą odporność na działanie temperatury.

5

Study of the Effect of Heat Stress on the Damage of the Fibre Matrix Interface of a Composite Material (T300/914) by Means of a Genetic Algorithm

Mokaddem A., Allami M., Temimi L., Boutaous A.

Fibres & Textiles in Eastern Europe

|

2012

|

Vol. 20, no. 6A (95)

108--111

EN

The aim of this paper is to develop an analytical model to evaluate the influence of thermal stress on damage to the fiber-matrix interface of a composite T300/914 from the properties of the fibre, as well as from the matrix and characteristics of the interfacial binding. The model developed by a genetic algorithm takes into account the temperature effects that result in the progressive degradation of the fibre-matrix. This work shows the influence of thermal stress beyond the critical threshold of damage to the interface, and that the matrix damage has an important influence on the damage to the interface compared to that of the fiber.

PL

Celem badań było opracowanie modelu analitycznego do oceny wpływu stresu termicznego na uszkodzenia warstwy międzyfazowej kompozytu T300/914 na podstawie właściwości włókien i matrycy oraz charakterystyki połączenia. Model opracowany przez algorytm genetyczny uwzględnia wpływ temperatury, który prowadzi do degradacji matrycy. Artykuł opisuje również wpływ stresu termicznego w warunkach krytycznych.