This document provides information about a composite materials course, including:
- The course code, title, credits, semester, and instructor
- Course objectives, evaluation system, and topics to be covered in each meeting
- Descriptions of the topics to be discussed each meeting, including introductions to composites, types of composites, manufacturing methods, and applications
- References for further reading on composite materials
It outlines the syllabus for a composite materials engineering course, with details on goals, assessments, meeting schedules, and content to be covered for each lesson.
Korosi
korosi adalah proses degradasi/deteorisasi/perusakan material yang terjadi disebabkan oleh lingkungan sekelilingnya. Adapun definisi korosi dari pakar lain : Perusakan material tanpa perusakan mekanis. Kebalikan dari metalurgi ekstraktif. Proses elektrokimia dalam mencapai kesetimbangan termodinamika suatu sistem.
JENIS KOROSI Korosi kimia (chemical corrosion), yaitu korosi yang terjadi dengan reaksi kimia secara murni. Biasanya terjadi pada temperatur tinggi atau dalam keadaan kering. Contoh: katup motor bakar Korosi elektrokimia (electrochemical corrosion), yaitu korosi yang terjadi bila reaksinya berlangsung dengan suatu elektrolit, yaitu cairan yang mengandung ion-ion. Reaksi berlangsung dengan adanya air/ uap air. Reaksi semacam inilah yang paling banyak terjadi pada reaksi korosi.
REAKSI TERJADINYA KOROSI Pada peristiwa korosi, logam mengalami oksidasi, sedangkan oksigen (udara) mengalami reduksi. Karat logam umumnya adalah berupa oksida atau karbonat. Rumus kimia karat besi adalah Fe2O3.nH2O, suatu zat padat yang berwarna coklat-merah. Ion besi(II) yang terbentuk pada anode selanjutnya teroksidasi membentuk ion besi(III) yang kemudian membentuk senyawa oksida terhidrasi, Fe2O3. xH2O, yaitu karat besi. Mengenai bagian mana dari besi itu yang bertindak sebagai anode dan bagian mana yang bertindak sebagai katode, bergantung pada berbagai faktor, misalnya zat pengotor, atau perbedaan rapatan logam itu.
FAKTOR YANG MEMPENGARUHI KOROSI 1. Kontak Langsung logam dengan H2O dan O2 2. Keberadaan Zat Pengotor 3. Kontak dengan Elektrolit 4. Temperatur 5. Ph 6. Metalurgi 7. Mikroba
Korosi
korosi adalah proses degradasi/deteorisasi/perusakan material yang terjadi disebabkan oleh lingkungan sekelilingnya. Adapun definisi korosi dari pakar lain : Perusakan material tanpa perusakan mekanis. Kebalikan dari metalurgi ekstraktif. Proses elektrokimia dalam mencapai kesetimbangan termodinamika suatu sistem.
JENIS KOROSI Korosi kimia (chemical corrosion), yaitu korosi yang terjadi dengan reaksi kimia secara murni. Biasanya terjadi pada temperatur tinggi atau dalam keadaan kering. Contoh: katup motor bakar Korosi elektrokimia (electrochemical corrosion), yaitu korosi yang terjadi bila reaksinya berlangsung dengan suatu elektrolit, yaitu cairan yang mengandung ion-ion. Reaksi berlangsung dengan adanya air/ uap air. Reaksi semacam inilah yang paling banyak terjadi pada reaksi korosi.
REAKSI TERJADINYA KOROSI Pada peristiwa korosi, logam mengalami oksidasi, sedangkan oksigen (udara) mengalami reduksi. Karat logam umumnya adalah berupa oksida atau karbonat. Rumus kimia karat besi adalah Fe2O3.nH2O, suatu zat padat yang berwarna coklat-merah. Ion besi(II) yang terbentuk pada anode selanjutnya teroksidasi membentuk ion besi(III) yang kemudian membentuk senyawa oksida terhidrasi, Fe2O3. xH2O, yaitu karat besi. Mengenai bagian mana dari besi itu yang bertindak sebagai anode dan bagian mana yang bertindak sebagai katode, bergantung pada berbagai faktor, misalnya zat pengotor, atau perbedaan rapatan logam itu.
FAKTOR YANG MEMPENGARUHI KOROSI 1. Kontak Langsung logam dengan H2O dan O2 2. Keberadaan Zat Pengotor 3. Kontak dengan Elektrolit 4. Temperatur 5. Ph 6. Metalurgi 7. Mikroba
Telah dilakukan sebuah penelitian berjudul Sintesis Komposit Polimer Elektrolit LiBOB Menggunakan Polimer PVdF – HFP Dengan Variasi Komposisi Filler TiO Sebagai Aplikasi Baterai Lihitum. Tujuan dari penelitian ini adalah untuk mengetahui sintesis komposit polimer elektrolit LiBOB, mengetahui karakteristik komposit polimer elektrolit LiBOB hasil sintesis, dan mengetahui aplikasi komposit polimer elektrolit LiBOB pada baterai lihitum.Sintesis LiBOB dapat dibuat dengan bahan – bahan polimer PVdF – HFP, garam LiBOB, dan filler TiO2 menggunakan metode casting pada sampel berbentuk slurry diatas plat kaca. Dibuat tiga variasi komposisi filler TiO2, PVdfF– HFP 70%(wt) LiBOB 30% (wt), dan filler TiO2 0% (wt); PVdfF– HFP 70%(wt) LiBOB 28% (wt), dan filler TiO2 2% (wt); dan PVdfF– HFP 70%(wt) LiBOB 25% (wt), dan filler TiO2 5% (wt). Dilakukan uji karakteristik dengan SEM untuk mengetahui bentuk morfologi, dengan EDX untuk mengetahui homogenitas, dan dengan CV untuk mengetahui reversibilitas ion. Sampel dengan komposisi PVdfF– HFP 70%(wt) LiBOB 25% (wt), dan filler TiO2 5% (wt) merupakan sampel yang paling dapat diaplikasikan pada baterai lihitum.
Struktur kolom komposit adalah struktur kolom yang terdiri dari beton bertulang dan diisi dengan profil baja. Mempunyai keuntungan pengerjaan yang cepat karena biasanya menggunakan balok baja sebagai struktur horizontalnya.
Image result for metal matrix composites
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A metal matrix composite (MMC) is composite material with at least two constituent parts, one being a metal necessarily, the other material may be a different metal or another material, such as a ceramic or organic compound. When at least three materials are present, it is called a hybrid composite.
Experimental evaluations and performance of the aluminum silicon carbide par...IAEME Publication
Stresses induced due to thermal mismatch between the metal matrix and the ceramic reinforcement in metal matrix composite may impart plastic deformation to the matrix there by
resulting in a reduction of the residual stresses. Thermal mismatch strains also may quite often crack
the matrix resulting in a relaxation of the residual stresses. The interface in MMCs is a porous, noncrystalline portion in comparison with the matrix or the reinforcement (metal matrix and ceramic reinforcement in this case).
Metal matrix composites (MMCs) possess significantly improved properties including highspecific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash is one of the most inexpensive and low density reinforcement available in large quantities as solid waste by-product during combustion of coal in thermal power plants. Hence, composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
2. PENDAHULUAN
Mata Kuliah : KOMPOSIT
Kode Mata Kuliah : E2034304
SKS : 3
Semester : Genap 2014/2015
Staf Pengajar : Rahmat Doni Widodo (RDW)
Tujuan Pengajaran :
Memahami jenis- jenis, sifat, proses pabrikasi
dan penggunaan dari material komposit
Sistem Evaluasi :
Kehadiran : 5 %
Tugas : 15 %
Ujian Tengah Semester (UTS) : 30 %
Presentasi : 15 %
Ujian Akhir Semester (UAS) : 35 %
3. SATUAN ACARA PENGAJARAN (SAP)
Pertemuan Tanggal Pokok Bahasan
1 5 Maret 2015
Maksud dan tujuan dibuatnya material komposit,
struktur, klasifikasi, konsep desain dan aplikasi material
komposit.
2 12 Maret 2015
Isotropy dan Anisotropy pada komposit, Karakteristik
Penguat dan Matrik, Unindirectional pada Lapisan (Ply),
Pabrikasi Woven, Mats dan Reinforce Matrix.
3 19 Maret 2015
Definisi struktur Sandwich, Sifat struktur Sandwich,
Pabrikasi dan desain struktur Sandwich.
4 26 Maret 2015
Konsep dasar desain, bentuk, kerusakan, dan sifat pada
struktur Laminate.
5, 6 dan 7
2, 9 dan 16 April
20015
Konsep dasar sifat mekanik, ketahanan pada: beban
dinamis, korosi, temperatur, lelah pada material
komposit.
8 23 April 20015 UJIAN TENGAH SEMESTER
4. SATUAN ACARA PENGAJARAN (SAP)
Pertemuan Tanggal Pokok Bahasan
9 30 April 2015
Sifat elektrik berupa konduktifitas, Volume tahanan
elektrik, Daya elektrik dan tahanan panas, Efek strain
terhadap sifat elektrik, Kuat sambungan mekanik
terhadap sifat elektrik pada material komposit.
10 7 Mei 2015
Konsep dasar Sifat thermal berupa: Expansi panas, Panas
jenis, dan konduktifitas panas pada material komposit.
11 21 Mei 20015
Proses pembuatan atau pabrikasi material komposit
melalui proses molding, dan proses selain molding.
12 dan 13
28 Mei dan 4 Juni
2015
Aplikasi material komposit untuk konstruksi transportasi
dan kepentingan lainnya.
14 dan 15 11 dan 18 Juni 2015
Prsentasi dari hasil review jurnal yang berhubungan
dengan Faktor-fakrot yang mempengaruhi sifat pada
material komposit melalui review journal penelitian.
25 Juni 2015 Minggu Tenang
16 2 Juli 2015 UJIAN AKHIR SEMESTER
5. References
Vincent K.S. Choo, Fundamentals of Composite
Materials, Knowen Academic Press Inc, 1990
Derek Hull, An Introduction to Composite Materials,
Cambridge University Press, 1981.
Deborah D.L. Chung, Composite Materials : Science and
Applications Ed.2, Springer-Verlag, 2010.
Suong V. Hoa, Principles of the Manufacturing of
Composite Materials, DEStech Publications Inc, 2009.
Sanjay K. Mazumdar, Composites Manufacturing :
Materials, Product and Process Engineering, CRC Press,
2002.
6. References
Daniel Gay, Suong V. Hoa, Stephen W. Tsai, Composite
Materials: Design and Applications, CRC Press, 2003.
Campbell F.C., Structural Composite Materials, ASM
International, 2010.
Ajayan P.M., Schadler L.S., and Braun P.V.,
Nanocomposite Science and Technology, Wiley-VCH
Verlag, 2003.
Abdul Hamid Zureich and Alan T. Nettles, Composite
Materilas : Testing, Design and Acceptance Criteria,
ASTM International, 2002.
Jurnal-jurnal hasil penelitian yang relevan dengan
bahan kajian.
7.
8. BAHAN KOMPOSIT
(COMPOSITE MATERIALS)
Merupakan penggabungan dua macam
material atau lebih dengan fase yang
berbeda.
Untuk skala atomic - mikro , logam, polimer, dan
keramik dapat digolongkan KOMPOSIT.
Pd KOMPOSIT bisa terjadi reaksi antar komponen
penyusunnya shg akan muncul fase ketiga yg
memiliki sifat berbeda dari fase pertma maupun
fase ke dua
9. Composite
• Combination of two or more individual
materials
• Design goal: obtain a more desirable
combination of properties (principle of
combined action)
– e.g., low density and high strength
10. Advantages of Composite Materials
• Stronger and stiffer than metals on a density
basis
• Capable of high continuous operating
temperatures
• Highly corrosion resistant
• Tailorable thermal expansion properties
• Tunable energy management characteristics
• Outstanding durability
• Low Observable
11. Disadvantages
- complex production methods
- difficult processing (cutting, forming)
- difficult joining
- often impossible to repair
- sometimes brittle
- high cost
12. Composites can be found in:
-Boat hulls
-The aerospace industry (structural components as well as
engines and motors)
-Automotive parts (panels, frames, dashboards, body
repairs)
-Bathtubs, hot tubs, swimming pools
-Cement buildings, bridges
-Surfboards, snowboards, skis
-Golf clubs, fishing poles, hockey sticks
-Trees are technically composite materials, plywood
-Electrical boxes, circuit boards, contacts
-Everywhere
13. Pd Komposit dikenal istilah :
MATRIK (fase Pertama)
REINFORCEMENT (fase Kedua)
Fase Pertama (Matrik) berfungsi sbg PENGIKAT
Fase Kedua(Reinforcement) berfungsi sbg PENGUAT
KLASIFIKASI KOMPOSIT:
1. CMC (Ceramic Matrix Composites)
2. MMC (Metal Matrix Composites)
3. PMC (Polymer Matrix Composites)
18. Metal Matrix Composites (MMC)
• Metal matrix composites (MMCs), as the name
implies, have a metal matrix. Examples of matrices
in such composites include aluminum, magnesium,
and titanium.
• Typical fibers include carbon and silicon carbide.
• Metals are mainly reinforced to increase or decrease
their properties to suit the needs of design. For
example, the elastic stiffness and strength of metals
can be increased, and large coefficients of
thermal expansion and thermal and electric
conductivities of metals can be reduced, by the
addition of fibers such as silicon carbide.
19. Advantages of MMC’s
• Metal matrix composites are mainly used
to provide advantages over monolithic
metals such as steel and aluminum.
These advantages include higher specific
strength and modulus by reinforcing low-
density metals, such as aluminum and
titanium; lower coefficients of thermal
expansion by reinforcing with fibers with
low coefficients of thermal expansion, such
as graphite; and maintaining properties
such as strength at high temperatures.
20. Advantages of MMC’s
• Advantages over polymer matrix
composites. These include higher elastic
properties; higher service temperature;
insensitivity to moisture; higher electric
and thermal conductivities; and better
wear, fatigue, and flaw resistances.
• The drawbacks of MMCs over PMCs
include higher processing temperatures
and higher densities.
21.
22. Fabrication Method
Fabrication methods for MMCs are varied. One
method of manufacturing them is diffusion bonding
which is used in manufacturing boron/aluminum
composite parts. A fiber mat of boron is placed
between two thin aluminum foils about 0.05 mm
thick. A polymer binder or an acrylic adhesive holds
the fibers together in the mat. Layers of these metal
foils are stacked at angles as required by the design.
The laminate is first heated in a vacuum bag to
remove the binder. The laminate is then hot pressed
with a temperature of about 500°C and pressure of
about 35 MPa in a die to form the required machine
element.
23.
24. Applications of MMC’s
• Space: The space shuttle uses
boron/aluminum tubes to support its
fuselage frame. In addition to
decreasing the mass of the space
shuttle by more than 145 kg,
boron/aluminum also reduced the
thermal insulation requirements because
of its low thermal conductivity. The mast
of the Hubble Telescope uses carbon-
reinforced aluminum.
25. • Military: Precision components of missile
guidance systems demand dimensional
stability — that is, the geometries of the
components cannot change during use.
Metal matrix composites such as
SiC/aluminum composites satisfy this
requirement because they have high
microyield strength. In addition, the
volume fraction of SiC can be varied to
have a coefficient of thermal expansion
compatible with other parts of the system
assembly.
26. • Transportation: Metal matrix
composites are finding use now in
automotive engines that are lighter than
their metal counterparts. Also, because
of their high strength and low weight,
metal matrix composites are the
material of choice for gas turbine
engines.
27. Ceramic Matrix Composites
(CMC)
Ceramic matrix composites (CMCs) have a
ceramic matrix such as alumina calcium
alumino silicate reinforced by fibers such
as carbon or silicon carbide.
28. Advantages of CMC’s
• High strength,
• Hardness,
• High service temperature limits for
ceramics,
• Chemical inertness, and
• Low density.
However, ceramics by themselves have low
fracture toughness. Under tensile or impact
loading.
29. Reinforcing ceramics with fibers, such as
silicon carbide or carbon, increases their
fracture toughness because it causes
gradual failure of the composite. This
combination of a fiber and ceramic matrix
makes CMCs more attractive for
applications in which high mechanical
properties and extreme service
temperatures are desired.
Advantages of CMC’s
30.
31. Manufacturing Method of CMC
One of the most common methods to
manufacture ceramic matrix composites is called
the hot pressing method. Glass fibers in
continuous tow are passed through slurry
consisting of powdered matrix material, solvent
such as alcohol, and an organic binder (Figure
1.31). The tow is then wound on a drum and dried
to form prepreg tapes. The prepreg tapes can now
be stacked to make a required laminate. Heating
at about 500°C burns out the binder. Hot pressing
at high temperatures in excess of 1000°C and
pressures of 7 to 14 MPa follows this.
32.
33. Carbon Carbon Composites
Carbon–carbon composites use carbon
fibers in a carbon matrix. These
composites are used in very high-
temperature environments of up to
3315°C, and are 20 times stronger and 30%
lighter than graphite fibers.
34. Carbon Carbon Composites
Carbon–carbon composites use carbon
fibers in a carbon matrix. These
composites are used in very high-
temperature environments of up to
3315°C, and are 20 times stronger and
30% lighter than graphite fibers.
35. Advantages of C-C Composites
• Carbon is brittle and flaw sensitive like
ceramics. Reinforcement of a carbon matrix
allows the composite to fail gradually and also
gives advantages such as ability to withstand
high temperatures, low creep at high
temperatures, low density, good tensile and
compressive strengths, high fatigue resistance,
high thermal conductivity, and high coefficient of
friction.
• Drawbacks include high cost, low shear strength,
and susceptibility to oxidations at high
temperatures.
36.
37. Processing a c–c composite
Low-pressure carbonization
A graphite cloth is taken, impregnated by resin
(such as phenolic, pitch, and furfuryl ester), and laid
up in layers. It is laid in a mold, cured, and trimmed.
The part is then pyrolized, converting the phenolic
resin to graphite. The composite is then
impregnated by furfuryl alcohol. The process drives
off the resin and any volatiles. The process is
repeated three or four times until the level of
porosity is reduced to an acceptable level. Each
time, this process increases its modulus and
strength. Because carbon–carbon composites
oxidize at temperatures as low as 450°C, an outer
layer of silicon carbide may be deposited.
38. • Mechanical fasteners: Fasteners needed for
high temperature applications are made of
carbon–carbon composites because they lose
little strength at high temperatures.
39. NATURAL FIBERS
• abaca, coconut, flax, hemp, jute, kenaf and sisal
are the most common — are derived from the
bast or outer stem of certain plants.
• They have the lowest density of any structural
fiber but possess sufficient stiffness and strength
for some applications.
• The automotive industry, in particular, is using
these fibers in traditionally unreinforced plastic
parts and even employs them as an alternative to
glass fibers. European fabricators hold the lead in
use of these materials, in part because regulations
require automobile components to be recyclable.
42. Natural fiber composites vs. synthetic fiber
composites
Study Materials Application Performance
Schmidt & Meyer
(1998)
Hemp-EPDM-PP
vs. GF-EPDM-
PP
Auto Insulation
component (Ford
car)
Hemp fibers are
able to replace
glass fibers
Diener & Siehler
(1999)
GF-PP vs. Flax-
PP
Auto car panel
(Mercedes A car)
Successfully
passed all test
Wotzel et al.
(1999)
Hemp – Epoxy
vs. ABS
Auto side panel Do not discuss
the performance
Corbiere-Nicollier
et al. (2001)
China reed-PP
vs. Glass-PP
Transport pallet Satisfying
service
requirement
Source : Joshi et al. (2003)
43. Weight Reduction
Component Study NFRP
component
Base
component
Auto side panel Wotzel et al. 820 g (hemp-
epoxy)
1125 g (ABS)
Auto insulation Schmidt &
Meyer (1998)
2.6 kg (hemp-
PP)
3.5 kg (GF-PP)
Transport-Pallet Corbiere-
Nicollier et al.
(2001)
11.77 kg (China
reed – PP)
15 kg (GF – PP)
Source : Joshi et al. (2003)
47. Mechanics Terminology
The approach to analyze the mechanical behavior
of composite structures is:
1. Find the average properties of a composite ply
from the individual properties of the
constituents. Properties include stiffness,
strength, thermal, and moisture expansion
coefficients. Note that average properties are
derived by considering the ply to be
homogeneous. This is called the micromechanics
of a lamina.
48. 2. Develop the stress–strain relationships for a
unidirectional/bidirectional lamina. Loads may
be applied along the principal directions of
symmetry of the lamina or off-axis. Also, one
develops relationships for stiffness, thermal and
moisture expansion coefficients, and strengths
of angle plies. Failure theories of a lamina
are based on stresses in the lamina and
strength properties of a lamina. This is called
the macromechanics of a lamina.