An innovative TEXT BOOK with simple interactive software PROMAL

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This innovative book provides a complete introduction to the mechanical behavior of
composites. Geared to upper-level and graduate students, or practicing engineers and scientists
interested in updating their knowledge, Mechanics of Composite Materials is a new
approach to the topic. Unlike old-style texts, this book introduces the basics of composites
through frequently asked questions the author answers from his considerable experience as a
professor and researcher in the field. The text is supplemented by user-friendly PROMAL
software, which allows readers to conduct studies, compare theories, design structures, and
quickly access the information in tables and graphs. Richly illustrated and filled with problems,
reviews, and examples, this is an excellent assessment of an exciting field.
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Chapter 1 - Introduction to Composite
Materials
Classify composites, introduce common types of fibers and matrices, and manufacturing,
mechanical properties and applications of composites
Recycling of composites
Introduce terminology used for studying mechanics of composites Chapter 2- Overview of
Composites
Develop stress-strain relationships for different types of materials
Develop stress-strain relationships for a unidirectional/bidirectional lamina
Find the engineering constants of a unidirectional/bidirectional lamina in terms of the stiffness
and compliance parameters of the lamina
Develop stress-strain relationships, elastic moduli, strengths, thermal and moisture expansion
coefficients of an angle ply based on those of a unidirectional/bidirectional lamina and the angle
of the ply
Chapter 3- Micromechanical Analysis
of a Lamina
Find the nine mechanical and four hygrothermal constants: four elastic moduli, five strength
parameters, two coefficients of thermal expansion and two coefficients of moisture expansion of
a unidirectional lamina from the individual properties of the fiber and the matrix, fiber volume
fraction, and fiber packing
Discuss the experimental characterization of the above nine mechanical and four hygrothermal
constants
Chapter 4- Macromechanical Analysis
of a Laminate
Develop relationships of mechanical and hygrothermal loads applied to a laminate to strains and
stresses in each lamina
Find the elastic stiffnesses of laminate based on the elastic moduli of individual laminas and the
stacking sequence
Find the coefficients of thermal and moisture expansion of a laminate based on elastic moduli,
coefficients of thermal and moisture expansion of individual laminas, and stacking sequence
Chapter 5- Failure, Analysis
and Design of Laminates
Establish the failure criteria for laminates based on failure of individual lamina in a laminate
Design laminated structures such as plates and thin pressure vessels subjected to in-plane and
hygrothermal loads
Introduce other mechanical design issues in laminated composites
Chapter 6- PROMAL for Windows
Software Package: A User's Guide
First, once students are required and tested in
conducting analysis of mechanics of composite
materials, the software is then introduced to
avoid repetition and tedious calculations.
Second, allow students to carry their own
parametric studies to see the effects of
variables on the performance of composites.
Third, give a tool to conduct "industrial" type
design of structures made of composite
materials.
The software is available in the classroom on a
computer connected to a projection system. It
is used to conduct parametric studies which are
shown both in tabular and graphical form. Many
a times students ask "what if" questions and
the instructor can now readily answer of those
questions now.
Since the present generation is more "hands on"
type, the class is held in a computer
laboratory once a week. This allows students
to carry their own numerical experiments. In
the last month of the class, the software is
used heavily to do open-ended design problems.
The final examination is a take-home real life
design problem.
Ten percent of the course grade is reserved for
the evaluation of the software collected
through E-mail. Feedback includes strengths
and weaknesses of the program, and most
importantly suggestions to improve the program.
The students have given excellent reviews for
the program.
Several computational problems are solved using
the software. Most problems are open ended and
students come up with several answers. Simple
designs of pressure vessels and leaf springs
do not take more than ten minutes to work out
with the PROMAL program, which would otherwise
take several hours by using a calculator. The
computer program still maintains the student's
need to think about the various inputs to the
program to get an optimum design. At the end
of the exercise, students and Dr. Kaw discuss
not only the various design alternatives but
also how students think differently.
There are three price structures:

Today's composite materials often outshine traditional materials; they are
lightweight, corrosion-resistant, and strong. Used in everything from aircraft structures to golf
clubs, and serving industries from medicine to space exploration, composites are an exciting field
of study for students, engineers, and researchers around the world. New applications of these
versatile materials are being found daily.
You are Visitor #
since November
26, 1996

TABLE OF CONTENTS
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Define a composite, enumerate advantages and drawbacks of composites over monolithic
materials, and discuss factors which influence mechanical properties of a composite
Review definitions of stress, strain, elastic moduli and strain energy
Develop concepts of volume and weight fraction of fiber and matrix, density and void fraction in
composites
Understand the code for laminate stacking sequence
Understand the significance of stiffness, and hygrothermal and mechanical response of special
cases of laminates
Show how to set up PROMAL on a personal computer
Show how to use PROMAL for
matrix algebra such as multiplication of matrices, solving a set of equations and finding inverse
of a matrix,
developing and maintaining a database for properties of unidirectional laminas,
conducting macromechanics of a lamina,
conducting micromechanics of a lamina,
conducting macromechanics of a laminate
Show by examples how to use each of the above programs

PROMAL

What is PROMAL?
PROMAL (Program for Micromechanical and
Macromechanical Analysis of Laminates) is an
interactive software tool used to complement
(not supplement) the senior level course --
Introduction to Mechanics of Composite
Materials. The objectives are the following:
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PROMAL software fits on a single 3.5" disk
which is given to each student in the beginning
of the semester. It is also available in all
the computer laboratories in the College of
Engineering.Who can buy PROMAL?
CAUTION: This software is distributed only as a THEORETICAL educational tool and is
exclusively for the following:
1. University instructors using PROMAL for teaching a course in Mechanics of Composite
Materials, or
2. University students using PROMAL to learn a course in Mechanics of Composite Materials,
or
3. Continuing education students using PROMAL to learn a formal course in Mechanics of
Composite Materials, or
4. Self-study students who are using PROMAL and a text book to learn a course in Mechanics of
Composite Materials and have taken a University level course in Strength of Materials.
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How do I Purchase PROMAL?
CAUTION: This software is distributed only as a THEORETICAL educational tool and is
exclusively for the following:
1. University instructors using PROMAL for teaching a course in Mechanics of Composite
Materials, or
2. University students using PROMAL to learn a course in Mechanics of Composite Materials,
or
3. Continuing education students using PROMAL to learn a formal course in Mechanics of
Composite Materials, or
4. Self-study students who are using PROMAL and a text book to learn a course in Mechanics of
Composite Materials and have taken a University level course in Strength of Materials.
Single Copy: Single copies are distributed only with the purchase of
the following text book -------
Mechanics of Composite Materials by Autar K. Kaw
Click to find how to order
One person may use it only on one computer.
Course License:$200.00 per year (includes shipping and handling; free
updates (only through WWW and ftp, and disks at renewal time) till license is maintained).
Instructors and students of one course (including multi-section courses) may use it
anywhere on one campus and at home (not at your work place). Send your check
to:
Professor Autar K. Kaw
ENB 118
Mechanical Engineering
Department
University of South Florida
Tampa, FL 33620-5350. MAKE CHEKCS
PAYABLE TO ME USF FOUNDATION
Important: Include your return and e-mail addresses, university or continuing education
affiliation, fax and daytime telephone numbers with your check.
Continuing Education Instructors: Please contact the author directly
for prices.


Promal for Windows-Matrix Algebra




Procedure:
Click on the Macromechanics of a Lamina Button in the Master Menu.
Click on the proper system of units for the input and output.
Click on Select Lamina from Lamina Properties Database Button to select the material properties
of the Graphite/Epoxy.
To analyze the lamina for the optimum fiber angle for the given load, select the Graph: Strength
Ratios vs. Angle of Ply Button. Enter the components of the stress vector. Once you enter these
values, you are presented with the first of four graphs showing the strength ratio as a function of
the angle of ply. The second graph shows the results of using the Maximum Stress failure
theory.
After inputting the given data, Promal produces the following graphical output







SOLUTION:
The maximum normal stress in a plate under
bending is given by
Stress = M t/(2 I)
where
M = bending moment (lb-in)
t = thickness of plate (in)
I = second moment of area (in^4)
For a rectangular cross-section, the second
moment of area is
I = b t^3/12
where
b = width of plate (in).
Using a factor of safety, F = 2 and given
b = 4 inches,
then the thickness of the plate using the
Maximum Stress criterion is
t= 0.9871 in
Now the designer wants to replace the 0.9871
inches thick aluminum plate by a plate of
maximum thickness 0.4935 inches (half that of
aluminum) made of laminated composites.
The bending moment per unit width is 3,250 lb-in.
Using the factor of safety of two, the plate is
designed to take a bending moment per unit
width of 6250 lb.
The simplest choices are to replace the
aluminum plate by an all Graphite/Epoxy
laminate or an all Glass/Epoxy laminate. Using
PROMAL program, the strength ratio for a single
0 degree ply for the above load for Glass/Epoxy
ply is
SR = 5.4942 E-5
Since the bending moment per unit width is
inversely proportional to the square of the
thickness of the plate, the minimum number of
plies required would be 135 which gives the
thickness of the all Glass/epoxy laminate as
t = 135 x 0.0049213
= 0.664 in.
The thickness of an all Glass/Epoxy laminate is
more than 0.4935 inches and is hence not
acceptable. Similarly for an all
Graphite/Epoxy a laminate, the minimum number
of plies required would be
n = 87 plies
which gives the thickness of the plate as
t = 87 x 0.0049213
= 0.42815 in.
The thickness of an all Graphite/Epoxy laminate
is less than 0.4935 inches and is hence
acceptable.
Even if an all graphite/epoxy laminate is
acceptable, Graphite/Epoxy is 2.5 times
costlier than a Glass/Epoxy, one would suggest
the use of a hybrid laminate. The question
which arises now is in what sequence the plies
should be stacked. In a plate under a bending
moment, the magnitude of ply stresses is
maximum on the top and bottom face. Since the
longitudinal tensile and compressive strengths
are larger in the Graphite/Epoxy ply then in a
Glass/Epoxy ply, one would put them as the
facing material and the Glass/Epoxy in the
core.
The maximum number of plies allowed in the
hybrid laminate is
= 0.4936/0.0049213
= 100 plies
Several combinations of 100 ply symmetric
hybrid laminates were subjected to the applied
bending moment. Minimum strength ratios in
each laminate stacking sequence were found. If
the strength ratios are greater than one, the
cost of the stacking sequence was determined.
The hybrid laminate with the lowest cost is [16
plies of Graphite/Epoxy, 68 plies of
Glass/Epoxy and 16 plies of Graphite/Epoxy].
The above example dictated the use of
unidirectional laminates. How will the design
change if there were multiple loads? Examples
of multiple loads include a leaf spring
subjected to bending moment as well as torsion,
a thin pressure vessel subjected to an internal
pressure to yield a biaxial state of stress.
In such cases, one may have a choice not only
of material systems or their combination but
that of orientation of plies as well. Since
there can be infinite combinations of angle
plies, attention may be focussed on angle plies
of 0, 90, 45 and -45 angle plies and their
combination thereof. This reduces the
possibilities to a finite number for a limited
number of material systems, but still the
number can be quite large to handle.
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Promal1.zip file- Updated promal.exe.
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The course starts with a one month long introduction to composites, although the
main emphasis of the course is on teaching the mechanics of composites. Aspects
covered include applications, mechanical properties, manufacturing, advantages and
drawbacks of various types of composites. These aspects are covered by using
professional videos such as "New Materials," "Composites Manufacturing," etc. Also, a
request letter sent by Professor Kaw to 300 companies associated with manufacturing,
applications and testing of composites in United States generated several promotional
videos ranging from filament winding to pultrusion, brochures, testing procedures,
specifications and design guidelines. Professor Kaw shows the videos in a classroom with a
TV and video recorder setup, and the videos are also available for check out by
students from the University Media Center.
Since composites are such a vast field, Professor Kaw teaches the introductory chapter
in the Introduction to Composites course using a newspaper question-answer style.
Although many were skeptical of this "USA-Today" approach, students have shown
great appreciation for this style. They learn faster and like the progressive style of
questions. This format also makes it a prime candidate for browsing on the WWW
pages. Many questions are based on queries by students in the classroom. New
questions can easily be added and answers can be updated at appropriate places.
A comprehensive WINDOWS-based software package called
PROMAL
has
been written at USF to complement the classroom instruction. Professor Kaw and several
Independent Study students have written this software package. This combined effort
has generated a quality product that caters to needs of both students as well as the
instructor. Since the national publication of PROMAL (DOS-version of PROMAL) in
1990, Professor Kaw and students have continually updated it several times into the present
form.
Students using PROMAL can instantly conduct pragmatic parametric studies,
compare failure theories, and have the information available in tables and graphs
instantaneously. The availability of the software allows Professor Kaw to answer many
questions instantaneously. PROMAL is more than a black box because it shows
intermediate results as well.
The students can use PROMAL anywhere on campus or home since it is
stored on a single 3.5" disk and can be set up in a couple of minutes. Several
universities in the nation are using this program. These include Florida State
University and Texas A & M. The software was also introduced in the Annual Summer
Faculty Development Program held jointly by NSF (National Science Foundation)
/ASEE (American Society of Engineering Education) to train faculty members in new
areas of engineering.
Out of three classes per week, Professor Kaw holds one of these classes per week in a
computer laboratory where each student has a computer and a video output connected
to the instructor's computer. This allows the student to first see an example done by
the instructor and then conduct his own numerical experiments.
The availability of the computer for each student becomes especially important
at the end of the semester where students design laminated composite structures.
Most problems are open ended and students come up with several answers. Simple
designs of pressure vessels and leaf springs do not take more than ten minutes to work
out with the PROMAL program, which would otherwise take several hours by using a
calculator. The computer program still maintains the student's need to think about the
various inputs to the program to get an optimum design. At the end of the exercise,
students and Professor Kaw discuss not only the various design alternatives but also how
students think differently.
Even with the use of new technology, the emphasis on teaching and testing the
student's knowledge about fundamentals has not changed. All tests are closed book
type and only nonprogrammable (but scientific) calculators are allowed in the test.
Only the final examination is a take-home design project where the student designs a
laminated composite structure using any available tools. These include handbooks,
material databases, mathematical packages such as MATHCAD and the PROMAL
software.
In the middle of the course, students get to visit companies that make composite
materials products. They see the development of the product from beginning to finish.
The timing of the visits works very well since it reinforces the fundamentals learned in
the classroom but also gets them to be enthusiastic about the designing of composites.
This course, which is a popular technical elective for Mechanical Engineering
students, has been taught every Spring Semester since 1988 with 15 to 20 students
enrolled each time. The course is currently attracting about 30 students. The positive
impact has been the placement of students in companies such as Boeing, General
Dynamics, Pratt & Whitney, etc., and the fostering of interest in graduate education in
the Mechanics of Composites field.
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EML 4562/ EML 5930
ROOM ENG 309 (M W F 8:00-8:50)
OBJECTIVES: Introduce to advanced composite materials and their applications.
Develop
fundamental relationships for predicting the mechanical and hygrothermal response of
multi-layered
materials and structures. Study micromechanical and macromechanical relationships for lamina
and
laminated materials with emphasis on continuous filament. Introduce material, structural and
strength
optimization to design laminated composite materials using user friendly software.
PRE-REQUISITES: Machine Design and Analysis I, EML 3500 or equivalent.
TEXTBOOK: Mechanics of Composite Materials by Autar K. Kaw
E-MAIL :
kaw@eng.usf.edu
OFFICE HOURS: MWF 10-11 AM. Any other time by appointment 974-5626.
HOMEWORK: All students should maintain a file of solved homework problems.
Homework problems include those assigned in the course handout as well as in the class. Bring
this file
to class everyday. Start each problem on a fresh page and write on only one side of the paper.
All
homework problems are due next week on the same day of the week. I will ask you to submit a
particular
assigned problem(s) in class at least 6 times during the semester. Due to the nature of the
submission
requirements, no late homework will be accepted. The lowest homework grade will be dropped.
GRADING POLICY:
EML 4562
Grade A - 80-100 Grade B - 70- 79 Grade C - 60- 69 Grade D - 50-59
Grade F - 0-49. Your final grade will be rounded off as follows at the end of the course. For
example,
84.000001-85.000000 will be rounded off as 85, and 84-84.000000999999999 will be rounded
off as 84.
EML 5930
Grade A - 90-100 Grade B - 80- 89 Grade C - 70- 79 Grade D - 60-69
Grade F - 0-59. Your final grade will be rounded off as follows at the end of the course. For
example,
84.000001-85.000000 will be rounded off as 85, and 84-84.000000999999999 will be rounded
off as 84.
COURSE SCHEDULE
CHAPTER 1 ------
Introduction to Composite Materials
All the examinations and tests stated above will be closed book and closed notes. A formula
sheet made
by the instructor may be allowed to be used in an examination. Course grades will be evaluated
on the
above percentages and a letter grade will be assigned to you as outlined in the University catalog
for
undergraduate students (1996-97).
MAKE-UP TEST POLICY: NO make-up tests will be given. However, in the event of
a
serious illness (physician's statement documenting severity of illness required), death in the
family or other
legitimate, documented, verifiable emergency resulting in the absence from a schedule test, a
student may
be given the same grade for the missed test as the score on the final examination. Notification of
absence
must be given prior to the commencement of the scheduled examination or test to me. Do not
presume
that your reasons for missing an examination or test are acceptable unless authorization is given
to
you.
PROMAL SOFTWARE
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How do I register the software?
Register by e-mail with the subject as "Registration" and body with name, university/continuing
education affiliation, postal address, e-mail address, telephone number and how you obtained a
copy of the software- a personal copy/ site license/ continuing education course.
OR
Register by mailing a post card with name, university/continuing education affiliation, postal
address, e-mail address, telephone number and how you obtained a copy of the software- a
personal copy/ site license/ continuing education course to:
ENB 118
Mechanical Engineering
Department
University of South Florida
Tampa, FL 33620-5350
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How do I get technical support?
Before getting technical support, check your manual and this page. For a
response to your technical needs, send your questions and comments by e-mail to:
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What are the commonly asked questions?
Question: When I run/setup PROMAL, I get an error - Use Graphics Server 2.1 or higher. How
do I solve this problem?
Answer: Copy gsw.exe and graph.vbx from the PROMAL directory to your Windows/system
directory. You may have older file versions of these two files. Be sure to make a backup of the
older files of gsw.exe and graph.vbx in a separate directory as you may need these if you have
programming languages such as Visual Basic VB 3.0 on your machine.
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What updates to PROMAL are available?
Check this page periodically for downloading latest promal.exe file. You cannot run PROMAL
just with the promal.exe file. Downloading is only for registered users.
PROMAL.EXE Updated Files
Promal.zip file- Original promal.exe.
Same as in sales before Nov. 30, 1996
Make a backup of the current promal.exe file on a disk for safekeeping. Download the
promal.zip file
by clicking here. Unzip it and call it promal.exe. Then copy it over
the current promal.exe file in your promal directory.
Same as in the book on "Mechanics of Composites" and sales after Nov. 30, 1996
Make a backup of the current promal.exe file on a disk for safekeeping. Download the
promal1.zip file
by clicking here. Unzip it and call it promal.exe. Then copy it over
the current promal.exe file in your promal directory.

Are help files to PROMAL available?
Help files to PROMAL will be available in May 1997 via ftp and www at this page.

How is Mechanics of Composites taught at USF?
Taught first in 1988, a conventional lecture course on Introduction to Composite
Materials is now a model course in the College of Engineering. The course now has
the following multidimensional components with a strong philosophy on using
technology only to "complement" the course content.
What is the course handout for Mechanics of Composite Materials at
USF?
CHAPTER 2 ------
Macromechanical Behavior of a Lamina
CHAPTER 3 ------
Micromechanical Behavior of a Lamina
CHAPTER 4 ------
Macromechanical Behavior of a Laminate
CHAPTER 5 ------
Design and Failure of a Laminate
Purchase Text Book|
Objective|
Table of Contents |
Chapter Objectives
PROMAL |
Restrictions PROMAL|
Purchase PROMAL |
System Requirements |
Programs |
Design Example
Registration |
Commonly Asked Questions
Updates |
Help files
GENERAL QUESTIONS
About the Author |
Course at USF |
Course Handout
Links to composite material sites with educational value
Carbon-Carbon Composites
Local Composite Company - Advanced Technology and Research
Composite Companies Listing and Links
Carbon-Carbon brake pads
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This home page was developed by Autar Kaw and Andrew Pappas
Copyright © 1997; Autar Kaw and Andrew Pappas