**Meet the editor**

Ezgi Günay is presently an Associate Professor in the Mechanical Engineering Department at Gazi University in Turkey. Ezgi Günay graduated from the Engineering Sciences Department (Applied Mechanics Department) of the Engineering Faculty at the Middle East Technical University in 1985 and received her Master of Science degree in 1989. She received her PhD degree at Gazi

University from the Mechanical Engineering Department in 1996. She has worked as a research assistant between 1993 and 1999 and studied academically as an assistant professor between 1999 and 2010 at the same department. She has been given courses in the following subjects: technical drawing, computer programming languages, engineering mathematics, statics, dynamics, strength of materials, numerical analysis, composite materials, finite element analysis, plate and shell theories, and elasticity. She has authored about 40 papers published in international conference proceedings and journals. She has a chapter published in *Progress in Sustainable Energy Technologies Vol. II* (2014). She has written two programming books (co-author) for the engineering students on Fortran language (*Workbook for FORTRAN 77* and *Programming Book for FORTRAN 77*) (2016). She has a chapter in the published book *Perusal of the Finite Element Method* (2016). She has received a certificate of appreciation for her outstanding contributions in reviewing journal papers from Elsevier publisher in 2016. She is presently working on the following subjects: finite element linear and nonlinear analyses of fiber composite-stiffened shell and plate structures, buckling analyses of fiber composite-stiffened plates, micromechanical investigation of fiber composites and natural composites, and experimental and numerical studies on wood materials.

Contents

**Preface VII**

**Brief Review 3** Ezgi Günay

**Composites 17**

Tatyana

and Gokce Ozdemir

**Plastic Composites 41**

**Natural Fiber Composites 57**

**Subjected to Flexural Loading 77**

**Section 1 Micromechanical Investigations on Natural Fiber Composites**

Chapter 1 **Introductory Chapter: Natural Fiber Plastic Composites - A**

Chapter 3 **Development of Hemp Fibers: The Key Components of Hemp**

Chapter 4 **Effect of Fiber Waviness on Tensile Properties of Sliver-Based**

Chapter 5 **Mechanical and Fracture Surface Analysis of Higher Viscous**

Yekta Karaduman, Huseyin Ozdemir, Nesrin Sahbaz Karaduman

Chernova Tatyana, Mikshina Polina, Salnikov Vadim, Ageeva Marina, Ibragimova Nadezda, Sautkina Olga and Gorshkova

Taweesak Piyatuchsananon, Baosheng Ren and Koichi Goda

**Epoxy/Multiwalled Carbon Nanotube Nanocomposites**

Aidy Ali, Risby M. Sohaimi and Ahmad H. Muhammad Ismail

**and Epoxy/MWCNT Nanocomposites 1**

Chapter 2 **Interfacial Modification of Hemp Fiber–Reinforced**

## Contents

**Preface XI**



#### **Section 2 Bio-based Composites and Recycled Products 87**

#### Chapter 6 **Waste and Recycled Textiles as Reinforcements of Building Materials 89**

Patricia Peña Pichardo, Gonzalo Martínez-Barrera, Miguel Martínez-López, Fernando Ureña-Núñez and Liliana I. Ávila-Córdoba

Preface

produced fiber reinforced materials."

trial area has been mentioned.

plastic composites.

Nano- and micro-sized natural fibers of vegetable origin are fully biodegradable in nature. However, the nano- and micro-sized synthetic fibers are fully man-made. Fiber-reinforced composites composed of stiffened fiber and matrix are well-known engineering materials. Fiber-reinforced materials have been used in industrial production. Natural fibers can be obtained from many sources in nature such as wool, sisal, ramie, kenaf, jute, corn tassel, hemp, grass, flax, cotton, coir, bamboo and abaca, banana, and sugarcane bagasse. Artificial fibers have been produced from more stiff materials such as glass, single-walled carbon nanotubes, double-walled carbon nanotubes, carbon, aramid, boron, and polyethylene (PE). The cyclic reusability of materials is an important qualification in protecting the environ‐ ment from waste pollution. Three important factors can be mentioned in terms of material properties in the recycling process. The first factor is "the rate of cyclic usage," the second one is "less material loss in each recycle," and the last one is "the role of waste products in the self-renewal of ecosystem." In engineering area, the usage of waste materials has taken into account in production of composite materials. The use of waste materials as particulatetype composite production is also possible in the industry. Fiber-reinforced materials can be grouped into two categories: "the natural fiber-reinforced materials" and "the artificially

The book consists of seven chapters. In the first four chapters of this book, the properties of green and natural fiber materials as a reinforcing material have been mentioned. In the fifth chapter, epoxy material fibers for double-walled carbon nanotubes have been examined and tested for artificial reinforcement, and crack problem solution has also been performed. In the sixth chapter, the properties of the natural fibers and their artificial use in "man-made" fiber composite materials have been explained. Additionally, recycling of reinforced cement and textile materials as a waste material has been examined. In the seventh chapter, the ad‐ vantages of sustainable bio-composites have been emphasized and their usage in the indus‐

The first chapter that belongs to the editor has been mainly subjected about the actual de‐ tailed literature survey on "Natural Fiber Plastic Composites." This review covers a general overview of the preparation phase (chemical procedures), test techniques (experiments), and results and conclusion summaries (the gainings) of current studies on hemp fiber-reinforced

In the second chapter, "Interfacial Modification of Hemp Fiber Reinforced Composites ", the micromechanical studies on the characteristics of fiber and matrix interface and stress distri‐ bution have been summarized by Dr. Yekta Karaduman and his colleagues. The content de‐ scribed the industrially used hemp fiber-based composites and their interfacial modifications

#### Chapter 7 **Natural Fibers for Sustainable Bio-Composites 107** Tri-Dung Ngo

## Preface

**Section 2 Bio-based Composites and Recycled Products 87**

Chapter 7 **Natural Fibers for Sustainable Bio-Composites 107**

**Materials 89**

**VI** Contents

Tri-Dung Ngo

Chapter 6 **Waste and Recycled Textiles as Reinforcements of Building**

Patricia Peña Pichardo, Gonzalo Martínez-Barrera, Miguel Martínez-

López, Fernando Ureña-Núñez and Liliana I. Ávila-Córdoba

Nano- and micro-sized natural fibers of vegetable origin are fully biodegradable in nature. However, the nano- and micro-sized synthetic fibers are fully man-made. Fiber-reinforced composites composed of stiffened fiber and matrix are well-known engineering materials. Fiber-reinforced materials have been used in industrial production. Natural fibers can be obtained from many sources in nature such as wool, sisal, ramie, kenaf, jute, corn tassel, hemp, grass, flax, cotton, coir, bamboo and abaca, banana, and sugarcane bagasse. Artificial fibers have been produced from more stiff materials such as glass, single-walled carbon nanotubes, double-walled carbon nanotubes, carbon, aramid, boron, and polyethylene (PE). The cyclic reusability of materials is an important qualification in protecting the environ‐ ment from waste pollution. Three important factors can be mentioned in terms of material properties in the recycling process. The first factor is "the rate of cyclic usage," the second one is "less material loss in each recycle," and the last one is "the role of waste products in the self-renewal of ecosystem." In engineering area, the usage of waste materials has taken into account in production of composite materials. The use of waste materials as particulatetype composite production is also possible in the industry. Fiber-reinforced materials can be grouped into two categories: "the natural fiber-reinforced materials" and "the artificially produced fiber reinforced materials."

The book consists of seven chapters. In the first four chapters of this book, the properties of green and natural fiber materials as a reinforcing material have been mentioned. In the fifth chapter, epoxy material fibers for double-walled carbon nanotubes have been examined and tested for artificial reinforcement, and crack problem solution has also been performed. In the sixth chapter, the properties of the natural fibers and their artificial use in "man-made" fiber composite materials have been explained. Additionally, recycling of reinforced cement and textile materials as a waste material has been examined. In the seventh chapter, the ad‐ vantages of sustainable bio-composites have been emphasized and their usage in the indus‐ trial area has been mentioned.

The first chapter that belongs to the editor has been mainly subjected about the actual de‐ tailed literature survey on "Natural Fiber Plastic Composites." This review covers a general overview of the preparation phase (chemical procedures), test techniques (experiments), and results and conclusion summaries (the gainings) of current studies on hemp fiber-reinforced plastic composites.

In the second chapter, "Interfacial Modification of Hemp Fiber Reinforced Composites ", the micromechanical studies on the characteristics of fiber and matrix interface and stress distri‐ bution have been summarized by Dr. Yekta Karaduman and his colleagues. The content de‐ scribed the industrially used hemp fiber-based composites and their interfacial modifications

in the consideration of shear stresses. In this century, determination of the most successful bonding between fibers and matrix by experimental and numerical studies is one of the most important research areas in mechanics and materials sciences. The aim of this chapter was to describe the methods to obtain a full transfer of applied external loads from weak matrix ma‐ terial to fibers as internal stress distributions. In this scope, firstly, the biological structure of the hemp fiber was explained. Mechanisms of fiber/matrix bonding in composite materials were outlined by theoretical and experimental scientific researches based on the literature. Samples of available techniques for the determination of interfacial strength were presented. Finally, the interface modification methods in the hemp fiber-reinforced composites were in‐ troduced.

the adverse effect of voids. In this study, the flexural strength and fracture toughness of the

In the sixth chapter, the industrial usage areas about "Waste and Recycled Textiles as Rein‐ forcements of Building Materials" were studied by researchers Patricia Peña Pichardo, Prof. Dr. Gonzalo Martínez-Barrera, and their colleagues. In this chapter, the outcomes of the lit‐ erature surveys were summarized by comparing the results of the recent scientific studies about this subject. In this chapter, the recently used basic topics on natural reinforcement applications were described, and these subjects were grouped under three subtitles such as (a) environmental impact of textile waste as a result of massive consumption of clothing, (b) recycling and reuse of textile waste, and (c) waste and recycled textile materials used as building materials. By learning the techniques for the use of natural textile fibers as rein‐ forcement in cement, improvements on the reinforcement-matrix interface in fiber compo‐ site materials, upgrading of natural polymers, obtaining polymer concrete by combining polymers and minerals, and improvement in the environmental properties were achieved.

In the seventh chapter titled "Natural Fibers for Sustainable Bio-Composites" by Dr. Tri-Dung Ngo, the advantages of natural fiber bio-composites used in the industrial applica‐ tions were demonstrated by literature survey. This study was based mainly on six topics as follows: (i) concept development, (ii) material design, (iii) material fabrication, (iv) product manufacturing, (v) marketing, and (vi) regulations. In this chapter, the potential utilization of natural fiber for the development of green polymer composite materials was emphasized with the objective to elucidate the possibility of using these bio-based materials for various important industrial applications. The other basic subtitles of the work were as follows: ther‐ moplastics, biopolymers, natural plant fiber polymer composites, eco-friendly bio-compo‐ sites from crop-derived plastics, and plant-derived fibers. The results of the collocated

Finally, we conclude that this book consists of mainly summarized three subject headings within the two specific book subsections : The first group contains the main subjects related to the natural and artificial fibers obtained by literature review; second, experimental and numerical studies are made in order to perform the necessary arrangements in the produc‐ tion stages and to establish a decision mechanism on the specification of the technical prop‐ erties of the fiber-reinforced composites. The third group of studies focused on the use of sustainable bio-composites and recycled textile wastes as reinforcements in construction.

The editor would like to express her thanks to Ms. Maja Bozicevic and Opr. Dr. Ayşe Günay

**Assoc. Prof. Dr. Ezgi Günay**

Mechanical Engineering Department

Gazi University Engineering Faculty

Preface IX

Ankara, Turkey

for their valuable supporting studies about the publishing of this book.

material at the break were improved with CNT additives.

In this chapter, these topics were presented and described in detail.

values were summarized in charts and tables.

**Acknowledgments**

In the third chapter titled "Development of Hemp Fibers: The Key Components of Hemp Plastic Composites," the results of recent scientific researches about this research area were explained by researchers Dr. Chernova T., Mikshina P., and their colleagues. The chapter's concept was based on the scientific researches for the material properties of processed green composite materials by applying the crop processing methodology. The growing strategies of the fibers are based on their extremely complex natural states within the planta. In this chapter, fiber and matrix combination in the green materials such as flax and hemp was ex‐ pressed by examining their growing stages in nature and with their located environmental conditions. Considering the material and geometrical properties of the cells, thick cell walls, and their layers, the final dimensions of secondary fibers were compared with the primary fibers. Basically, in this research, studies were explained in detail by declaring the basic two concepts. The first one was the intrusive elongation, and the second was the deposition of thick cell wall layers. The microscopic views and pictures were given for detailed informa‐ tion about the mentioned results.

The fourth chapter titled "Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites" by Prof. Dr. Eng. Koichi Goda and his team presented the results of their original research by explaining the two different specimen preparation methods. The mentioned two methods were different from each other as the sliver-based natural fiber composites with and without fiber waviness. The tensile test results showed that tensile strengths of direct method (DM) specimens accompanied by the fiber waviness were lower than those of sheet laminate method (SLM) specimens. The properties of fiber waviness on the specimens were quantified by two types of spatial autocorrelation analyses: the first one was Local Moran's I and the second was Local Geary's C. In the research, three-dimensional finite element analysis (3D FEA) was used to obtain the stress distribution numerically. At the end of the study, two failure criteria "Tsai-Hill" and "maximum stress" were used to discuss the tensile failure modes of the fiber composite material.

The fifth chapter titled "Mechanical and Fracture Surface Analysis of Higher Viscous Epoxy/ Multi-Walled Carbon Nanotube Nano-Composites Subjected to Flexural Loading" waspre‐ sented by Prof. Dr. Aidy Ali and PhD degree student and researcher A.H. Muhammad Ismail and M.S. Risby. In their study, the results of the developing fracture surface in the fiber com‐ posite material were explained by experimental studies. The effects of MWCNT weight per‐ centage (wt%) to flexural and fracture toughness properties were investigated for Mode I fracture behavior. In the chapter content, two important points were explained in an order: firstly, the significant enhancement as achieving the optimum state of dispersion and, second‐ ly, the interfacial adhesion between epoxy and MWCNT. It was declared that the well-dis‐ persed MWCNTs could easily alleviate the stress concentration of the matrix and eliminate the adverse effect of voids. In this study, the flexural strength and fracture toughness of the material at the break were improved with CNT additives.

In the sixth chapter, the industrial usage areas about "Waste and Recycled Textiles as Rein‐ forcements of Building Materials" were studied by researchers Patricia Peña Pichardo, Prof. Dr. Gonzalo Martínez-Barrera, and their colleagues. In this chapter, the outcomes of the lit‐ erature surveys were summarized by comparing the results of the recent scientific studies about this subject. In this chapter, the recently used basic topics on natural reinforcement applications were described, and these subjects were grouped under three subtitles such as (a) environmental impact of textile waste as a result of massive consumption of clothing, (b) recycling and reuse of textile waste, and (c) waste and recycled textile materials used as building materials. By learning the techniques for the use of natural textile fibers as rein‐ forcement in cement, improvements on the reinforcement-matrix interface in fiber compo‐ site materials, upgrading of natural polymers, obtaining polymer concrete by combining polymers and minerals, and improvement in the environmental properties were achieved. In this chapter, these topics were presented and described in detail.

In the seventh chapter titled "Natural Fibers for Sustainable Bio-Composites" by Dr. Tri-Dung Ngo, the advantages of natural fiber bio-composites used in the industrial applica‐ tions were demonstrated by literature survey. This study was based mainly on six topics as follows: (i) concept development, (ii) material design, (iii) material fabrication, (iv) product manufacturing, (v) marketing, and (vi) regulations. In this chapter, the potential utilization of natural fiber for the development of green polymer composite materials was emphasized with the objective to elucidate the possibility of using these bio-based materials for various important industrial applications. The other basic subtitles of the work were as follows: ther‐ moplastics, biopolymers, natural plant fiber polymer composites, eco-friendly bio-compo‐ sites from crop-derived plastics, and plant-derived fibers. The results of the collocated values were summarized in charts and tables.

Finally, we conclude that this book consists of mainly summarized three subject headings within the two specific book subsections : The first group contains the main subjects related to the natural and artificial fibers obtained by literature review; second, experimental and numerical studies are made in order to perform the necessary arrangements in the produc‐ tion stages and to establish a decision mechanism on the specification of the technical prop‐ erties of the fiber-reinforced composites. The third group of studies focused on the use of sustainable bio-composites and recycled textile wastes as reinforcements in construction.

#### **Acknowledgments**

in the consideration of shear stresses. In this century, determination of the most successful bonding between fibers and matrix by experimental and numerical studies is one of the most important research areas in mechanics and materials sciences. The aim of this chapter was to describe the methods to obtain a full transfer of applied external loads from weak matrix ma‐ terial to fibers as internal stress distributions. In this scope, firstly, the biological structure of the hemp fiber was explained. Mechanisms of fiber/matrix bonding in composite materials were outlined by theoretical and experimental scientific researches based on the literature. Samples of available techniques for the determination of interfacial strength were presented. Finally, the interface modification methods in the hemp fiber-reinforced composites were in‐

In the third chapter titled "Development of Hemp Fibers: The Key Components of Hemp Plastic Composites," the results of recent scientific researches about this research area were explained by researchers Dr. Chernova T., Mikshina P., and their colleagues. The chapter's concept was based on the scientific researches for the material properties of processed green composite materials by applying the crop processing methodology. The growing strategies of the fibers are based on their extremely complex natural states within the planta. In this chapter, fiber and matrix combination in the green materials such as flax and hemp was ex‐ pressed by examining their growing stages in nature and with their located environmental conditions. Considering the material and geometrical properties of the cells, thick cell walls, and their layers, the final dimensions of secondary fibers were compared with the primary fibers. Basically, in this research, studies were explained in detail by declaring the basic two concepts. The first one was the intrusive elongation, and the second was the deposition of thick cell wall layers. The microscopic views and pictures were given for detailed informa‐

The fourth chapter titled "Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites" by Prof. Dr. Eng. Koichi Goda and his team presented the results of their original research by explaining the two different specimen preparation methods. The mentioned two methods were different from each other as the sliver-based natural fiber composites with and without fiber waviness. The tensile test results showed that tensile strengths of direct method (DM) specimens accompanied by the fiber waviness were lower than those of sheet laminate method (SLM) specimens. The properties of fiber waviness on the specimens were quantified by two types of spatial autocorrelation analyses: the first one was Local Moran's I and the second was Local Geary's C. In the research, three-dimensional finite element analysis (3D FEA) was used to obtain the stress distribution numerically. At the end of the study, two failure criteria "Tsai-Hill" and "maximum stress" were used to

The fifth chapter titled "Mechanical and Fracture Surface Analysis of Higher Viscous Epoxy/ Multi-Walled Carbon Nanotube Nano-Composites Subjected to Flexural Loading" waspre‐ sented by Prof. Dr. Aidy Ali and PhD degree student and researcher A.H. Muhammad Ismail and M.S. Risby. In their study, the results of the developing fracture surface in the fiber com‐ posite material were explained by experimental studies. The effects of MWCNT weight per‐ centage (wt%) to flexural and fracture toughness properties were investigated for Mode I fracture behavior. In the chapter content, two important points were explained in an order: firstly, the significant enhancement as achieving the optimum state of dispersion and, second‐ ly, the interfacial adhesion between epoxy and MWCNT. It was declared that the well-dis‐ persed MWCNTs could easily alleviate the stress concentration of the matrix and eliminate

discuss the tensile failure modes of the fiber composite material.

troduced.

VIII Preface

tion about the mentioned results.

The editor would like to express her thanks to Ms. Maja Bozicevic and Opr. Dr. Ayşe Günay for their valuable supporting studies about the publishing of this book.

> **Assoc. Prof. Dr. Ezgi Günay** Gazi University Engineering Faculty Mechanical Engineering Department Ankara, Turkey

**Section 1**

**Micromechanical Investigations on Natural Fiber**

**Composites and Epoxy/MWCNT**

**Nanocomposites**
