This document discusses the course MDPN452 Mechanics of Composite Materials, taught by Dr. Mohammad Tawfik. It covers topics related to micromechanics of composites including the relationship between composite and constituent material properties, designing composites to achieve desired stiffness and strength, assumptions of micromechanics models, approaches to determining elastic properties like stiffness and Poisson's ratio, and models for predicting strength in tension and compression. Students are assigned homework to research models of tensile and compressive failure in composites and compare them to experimental data.
The fabrication methodology of a composite part depends mainly on three factors:
(i) the characteristics of matrices and reinforcements,
(ii) the shapes, sizes and engineering details of products, and
(iii) end uses.
The composite products are too many and cover a very wide domain of applications ranging from an engine valve to an aircraft wing.
The fabrication technique varies from one product to the other.
Autoclave is a closed vessel (Round or Cylindrical) in which processes occur under simultaneous application of high temperature and pressure. Autoclave molding technique is similar to vacuum bag and pressure bag molding method with some modifications. This method employs an autoclave to provide heat and pressure to the composite product during curing.
Fracture and failure analyses of plastics and reinforced plasticsPadmanabhan Krishnan
This ppt describes the structure property correlationship between structure, microstructure and the observed properties of plastics and reinforced plastics./ Fracture , failure analysis and fractography are discussed in details.
The fabrication methodology of a composite part depends mainly on three factors:
(i) the characteristics of matrices and reinforcements,
(ii) the shapes, sizes and engineering details of products, and
(iii) end uses.
The composite products are too many and cover a very wide domain of applications ranging from an engine valve to an aircraft wing.
The fabrication technique varies from one product to the other.
Autoclave is a closed vessel (Round or Cylindrical) in which processes occur under simultaneous application of high temperature and pressure. Autoclave molding technique is similar to vacuum bag and pressure bag molding method with some modifications. This method employs an autoclave to provide heat and pressure to the composite product during curing.
Fracture and failure analyses of plastics and reinforced plasticsPadmanabhan Krishnan
This ppt describes the structure property correlationship between structure, microstructure and the observed properties of plastics and reinforced plastics./ Fracture , failure analysis and fractography are discussed in details.
RTM is a low-pressure molding process, where a mixed resin and catalyst are injected into a closed mold containing a fiber pack or preform . when the resin has cured the mold can be opened and finished component removed.
Presentation for Fiber Composites course. Outlines the failure theories used in composite failure analysis and methods to design composite materials based on these failure theories.
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.
LARGE PARTICLE REINFORCED COMPOSITE ,,,An Overview
Seminar done as a part of METALLURGY AND MATERIAL SCIENCE.
Good PPT to study,
included most of the points to study
HASEEB KM
S3 ME
MUTHOOT INSTITUTE OF TECHNOLOGY AND SCIENCE, COCHIN
Pultrusion is a continuous process for manufacture of composite materials with constant cross-section.
It is more widely used in industries where there is a continuous demand of the product
RTM is a low-pressure molding process, where a mixed resin and catalyst are injected into a closed mold containing a fiber pack or preform . when the resin has cured the mold can be opened and finished component removed.
Presentation for Fiber Composites course. Outlines the failure theories used in composite failure analysis and methods to design composite materials based on these failure theories.
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.
LARGE PARTICLE REINFORCED COMPOSITE ,,,An Overview
Seminar done as a part of METALLURGY AND MATERIAL SCIENCE.
Good PPT to study,
included most of the points to study
HASEEB KM
S3 ME
MUTHOOT INSTITUTE OF TECHNOLOGY AND SCIENCE, COCHIN
Pultrusion is a continuous process for manufacture of composite materials with constant cross-section.
It is more widely used in industries where there is a continuous demand of the product
The important points of composite materials are mentioned. This file includes, what is composite materials, its classifications, applications, advantages and disadvantages.
Numerical Response for Initial Value Problems using Newmark Method.
#WikiCourses
https://wikicourses.wikispaces.com/Topic+Initial+Value+Problems
https://eau-esa.wikispaces.com/Topic+Initial+Value+Problems
How to derive the finite element model using the stationary functional approach?
Application to bars and beams!
#WikiCourses
https://wikicourses.wikispaces.com/TopicX+Stationary+Functional+Approach
https://eau-esa.wikispaces.com/Topic+Stationary+Functional+Approach
FEM: Nonlinear Beam Deflection Model (with Temperature)Mohammad Tawfik
Derivation and solution of the nonlinear finite element model of a beam under thermal loading.
#WikiCourses
https://wikicourses.wikispaces.com/TopicX+Nonlinear+Solid+Mechanics
https://eau-esa.wikispaces.com/Topic+Nonlinear+Solid+Mechanics
Brief description of current state of drones and some future challenges.
The presentation is prepared for delivery in the "Interact with Today's World" conference held in Bibliotica Alexandria 5-6 August 2016
Why would a company hire a trainer? To produce a change. The trainer by default is
an agent for change. Regardless of any results a trainer may accomplish, the bottom line is a
measurable change in employees’ performance.
What is marketing?
How to find out about customers?
How to reach them?
How to get them to know about you?
What is a product life cycle?
How about Marketing strategies?
Learn more ...
http://AcademyOfKnowledge.org
Finite Element Analysis of the Beams Under Thermal LoadingMohammad Tawfik
A report on the finite element analysis of a beam under thermal loading. Nonlinear deflections and solution procedures covered.
#WikiCourses
https://wikicourses.wikispaces.com/TopicX+Nonlinear+Solid+Mechanics
https://eau-esa.wikispaces.com/Topic+Nonlinear+Solid+Mechanics
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
2. MDPN452
Dr. Mohammad Tawfik
Micromechanics
• The basic question of micromechanics is:
what is the relationship of the composite
material properties to the properties of the
constituents?
3. MDPN452
Dr. Mohammad Tawfik
The Design Question!
• How can the percentages of the
constituent materials be varied so as to
arrive at the desired composite stiffness
and strength?
4. MDPN452
Dr. Mohammad Tawfik
Definitions
• Macromechanics: The study of composite
material behavior wherein the material is
assumed homogeneous and the effects of
the constituent materials are detected only
as averaged apparent properties of the
composite material.
5. MDPN452
Dr. Mohammad Tawfik
Definitions
• Micromechanics: The study of composite
material behavior wherein the interaction
of the constituent materials is examined in
detail as part of the definition of the
behavior of the heterogeneous composite
material.
7. MDPN452
Dr. Mohammad Tawfik
Micromechanics Objective
• To answer the questions set by
micromechanics, the objective becomes:
– Determine the elastic moduli or stiffness or
compliances of a composite material in terms
of the elastic moduli of the constituent
materials
( )mimfifii VPVPPP ,,,=
9. MDPN452
Dr. Mohammad Tawfik
Basic Assumptions
• The lamina:
– Initially stress-free, macroscopically homogeneous,
linearly elastic, macroscopically orthotropic
• The fibers:
– Homogeneous, regularly spaced, linearly elastic,
perfectly aligned, Isotropic, perfectly bonded
• The matrix:
– Homogeneous, Isotropic, linearly elastic, void-free
10. MDPN452
Dr. Mohammad Tawfik
Representative Volume
• The smallest region or piece of material
over which the stresses and strains can be
regarded as macroscopically uniform and
yet the volume still has the correct
proportions of fiber and matrix
12. MDPN452
Dr. Mohammad Tawfik
Most Prominent Assumptions
• In fibre direction, strain in fibres and matrix
are equal
• Normal to fibre direction, stresses in matric
and fibre are equal
23. MDPN452
Dr. Mohammad Tawfik
Strength
• “A chain is as strong as its weakest link”
• When the composite material gets loaded,
all its components get loaded with different
stresses
• Nevertheless, strength prediction of the
composite materials have not yet reached
the accuracy level of the stiffness
prediction. i.e. Open research area!
24. MDPN452
Dr. Mohammad Tawfik
Longitudinal Tensile Strength
• Main assumptions:
– All fibres have the same strength
– Fibres and matrix behave linearly
– Fibres are brittle when compared to matrix
– Fibres are stiffer than matrix
25. MDPN452
Dr. Mohammad Tawfik
Longitudinal Tensile Strength
• The stress that will cause the fibres to fail:
• Where is the stress in the matrix as
the fibres reach their ultimate stress.
• From that:
mmffut VV *
1 σσσ +=
f
m
fum
E
E
σσ =*
+= m
f
m
ffut V
E
E
Vσσ 1
28. MDPN452
Dr. Mohammad Tawfik
Minimum and Critical Vf
• From the graphs, and using the previous
equations, we may calculate:
*
*
mfu
mmu
criticalfV
σσ
σσ
−
−
=−
*
*
max
mmufu
mmu
fV
σσσ
σσ
−+
−
=
29. MDPN452
Dr. Mohammad Tawfik
Longitudinal Compressive
Strength
• In compression, the failure is dominated
by buckling of the fibres!
• Long fibres that are supported by softer
matrix material tend to buckle causing
what is called Microbuckling
• Microbuckling causes great reduction in
the compression stiffness of the composite
material
34. MDPN452
Dr. Mohammad Tawfik
Homework #3
• Read the papers provided to you
• Read section 4.4 in textbook
• Collect more papers evolving the same topics (at
least 3 per topic)
• Write down a report on each topic
• Due dates:
– Tensile Failure; axial and transverse
– Compressive failure ; axial and transverse
(19/10/2013 23:59)
35. MDPN452
Dr. Mohammad Tawfik
Report should include
1. Introduction to the topic (need, problems, history, etc...)
2. Models available in literature (Including the detailed
derivation of at least one of the models)
3. Results obtained from different models compared to
experimental results (direct from available literature)
4. Conclusions about the models and their accuracy
5. References and bibliography