Mock FEs
An Extra Credit Option
These Slides Contains Examples and Figures from Text Books and Test Guides
And images collected around the internet
What Will the FE Be Like?
•
A marathon
• Old Paper tests are being
Replaced by computer based
Tests
• The test is now 6 hours
– But only 5 hours and 20 minutes for questions
– The exam is shorter
– but more sinister
– Old format
• Morning 120 questions at 2 min/question
• Afternoon 60 questions at 4 min/question
• Organized by subject and difficulty
– New format
• One session 110 question 2 min 54 sec/question
• Subjects are scrambled
• Difficulty is scrambled
I Just Finished Taking
My FE
Using Computers
You will have a computer key board, a 24 inch
Screen, a calculator, a 10 page dry erase board
For work, and a dry erase marker
(no paper – no pencil – no cell phone)
The test will be on the screen
Your FE exam book will be a searchable
Electronic file
You will likely split your screen
A 6 Hour Appointment and Only 5
hr. 20 minutes on the Test
• You have an appointment time
– They have even less a sense of humor than me
about you being late
• Your first few minutes are
To sign non-disclosure forms
That you will not memorize
And publish the test
Like I can even remember
My name after that.
The Missing 40 Minutes
• There will be an orientation time (about 8
minutes)
– Make sure you know how to advance back and
forth
– Know how to enter search commands
– Know how to flag questions for easy returns to
questions
– Set your timer clock
– Check your dry erase pen
More Missing Time
• After about 55 questions the computer will
prompt you to review and save your work
– You then get a 25 minute break
• You may have brought a lunch you
• Have outside the room
• After you save you have no more access to the
first 55 questions
• If your not back in 25 minutes your timer starts
without you
• If you get back early it won’t increase your total
test time
Simulating an FE Experience
• We will not provide you 24 inch computer
monitors
– Your stuck with paper
• We will not test you for 5 hours and 20
minutes
– We only really care that you ace the Mechanics of
Materials Questions
• You will have your paper FE book and scratch
paper
Your Format
• You will have 16 questions
– But only 12 of them are Mechanics of Materials
– Your task will be to pass over the non-Mechanics
of materials questions
• Just put a line through A-D
• In the real test you may flag questions to return to
– The real test will have subjects mixed so you may
need to have some selectivity
• Remember pass happens at roughly 65% right
• Questions are A to D mark your choice clearly
Timing Your Mock FE
• FE questions average 2 minutes 54 seconds
• You will have 12 counter questions
– We will allow 3 minutes
– The extra is for throwing out the non-Mechanics
of Materials questions
• You will have 36 minute runs on each mock
F.E.
How Many Tries Do I Get
• We will Schedule 6 mock F.E.’s
– You can only count 4
– The expectation is that not everyone will be able
to make every session
– There is also an expectation that the first time you
try it – you’ll get creamed.
How Do I Pass?
• Get 8 out of 12 correct 67%
What are the Prizes
• Lets First look at Your Point Structure
– 15 quizzes for 20%
– Your lowest gets dropped so grade is best 13
– You can use up to 2 FE passes to replace to replace
other quizzes with 100s
• Homework
– 25 homeworks for 25%
I got mine in a box of
– Your lowest gets dropped so grade is best 24 Cracker Jack
– You can use 2 more FE passes to replace other
homeworks with 100s
You don’t want to know
Where I got mine.
Does this mean I didn’t pass?
What Are the Prizes?
• The Grand Slam – Pass 4 Mock F.E.s
– You get 100% on your final – without taking it!
– You get your lowest 2 quizes replaced by 100s
– You get your lowest 2 homeworks replaced by
100s
Are There Benefits for Being a
Genius
Yes - If you pass a lowest score turns
Into 100% (pass means got 8/12)
What if I get 9/12?
0.75/0.67 = 1.12
Your lowest score gets replaced with 112%
What if I get 12/12?
1.00/0.67 = 1.49
Your lowest score gets replaced with 149%
(You get the drill)
The FE Left Me Feeling
Like This Too!
Some Strategic Ideas
The 3 Pass Method
1- Pass one – get all the easy ones
You can do in one step without any
Struggle to find formula’s
(on the way through flag those you know
How to do but might need more time)
In the mock exam – dump all the wrong
Subject questions
2- Pass two – go back and nail all the ones
You know how to solve but have to search
Formulas and make more steps
3- Pass three – last perhaps 5 minutes –
Guess (use common sense narrowing to improve
Your odds – Leave no answer undone
The Mission Control Pad
Use one page of your note pad
To write yourself notes and tips
As you make your passes.
What Do I Do With Hard Problems?
Some Problems Look Hard but have
Non-obvious “make it easy” tricks
What is the reaction at A in the
X direction?
Some Hard Looking Problems
Dump Extra Information on You
Just What I Had
I Mind.
It wants you
To go into
An involved
Thermal
Stress problem
Oh Crap
Last Possibility for Hard Problem
You are not suppose to be
Able to Finish the Test in the
Allotted time.
Some problems are there just
To bleed their victims to death
On time - narrow the field and
Guess.
Study Strategy
Don’t Cram
Aim to Gear Up Over an 8
Week period
I crammed
Look What Happened
Don’t Freak-Out
The FE Book Contains
Mostly dump on information.
Only a few things are critical
Practice the Fundamentals
Use a good study guide to review basics
And spend time doing problems – Pace
And Discipline.
Home Stretch Preparations
Eat well the day before
Decompress
Get a Good Nights Sleep
Every Dog Has His Day
Mine is Tomorrow
Allow generous time to get to
The test center without rushing
Allow a little relax time when you
Get there.
Oh God – I Promise
To be good if you let
Me pass
Typical Distribution
General Engineering Exam
Math and Engineering Math 12-18 Problems
Probability and Statistics 6 – 9 Problems
Chemistry 7 – 11 Problems
Instrumentation and Data Acquisition 4 – 6 Problems
Ethics in Professional Practice 3 – 5 Problems
Safety Health and Environment 4 – 6 Problems
Engineering Economics 7 – 11 Problems (around 20-25% of PE)
Statics 8 – 12 { We include some of these }
Dynamics (looks a lot like Physics) 7 - 11
Rest of the Distribution
Mechanics of Materials 8 – 12
Materials Science 6 – 9 (Mechanics of Materials Helps Here)
Fluid Mechanics Liquids 8 – 12
Fluid Mechanics Gases 4 – 6
Electric Power and Magnetism 7 – 11
Heat Mass and Energy Transfer 9 - 14
So What Is On The Good Part?
• You need to do the problems that are Statics or
Mechanics of Materials
– (the line can be pretty fuzzy anyway)
• There are problems I told you to know by heart
–
–
–
–
–
–
Definition of Stress
Definition of Strain
Young’s Modulus
Shear Modulus
Poisson’s Ratio
Hooke’s Law
The Thermal Strain Problem
First Page of Mechanics
Of Materials
More on Thermal Strain Problem
Fifth Page of Mechanics of
Materials to get Coefficients
Of Thermal Expansion if not
Given.
Thermal Expansion With Constraint
Problem
Immovable wall
The rod would like to expand – but can’t
The result is thermal stress
1- Calculate how much it would expand if there
Were no constraint.
2- Find the force that needs to be applied to reverse
The expansion
From page 1 of Mechanics
Of Materials
Immovable wall
3- Use definition of stress to get the stress if the
Problem calls for it.
From page 1 of Mechanics
Of Materials
The Statically Indeterminate Problem
Duplicate forces can cause us to run out of statics equations
Before we actually complete our solution.
This problem is illustrated with this example
- We have only one sum of forces Y = 0 equation
- We have two forces Y pushing up
Solving the Problem
You remove one of the constraints and then calculate the
Deformation that would happen if there were only one
Support.
Of course you know that deformation doesn’t really occur
That way. You now add back enough of the removed force
To counter the deformation.
This leaves you with one unknown force and one static
Equation.
The Torsion Problem
Version one – Torsion Twists Something
What about Me?
I can’t Look
Bottom of Page 4 of Mechanics of Materials
Where Do I Get J
Table at the End of Statics section
Where Do I Get G
Most of the time it is as plain as the nose on
Your face – Its in the problem.
When its not look at the material properties
Table on page 5 of Mechanics of Materials
Section
The Next Torsion Problem is
the find the Shear Stress Version
For a Regular
Shaft
For a thin walled
shaft
How Is Torsional Shear Stress
Distributed?
Zero at the center rising linearly to the
Outside edge.
The Pressurized Tank Problem
Thick walled cylinder – axial, hoop
And radial
Page 1 Mechanics of Materials
The Thin Walled Cylinder
Top of Page 2
Hoop
Stress
Axial
Stress
Find the Centroid
Just the area weighted average
Of the centroids of the component
Areas.
This is made up of 3 rectangles.
You know the area and centroid of each
Over-all Centroid = (Area1*centroid1 + Area2*centroid2+Area3*centroid3)/Total area
Find the Moment of Inertia
Get the moment of inertia
Of the component areas
(formulas at the end of Statics)
Transfer the components to the common
Axis with the Parallel Axis Theorem
Add them up.
Smores Circle
State of Stress at One Point Only!
IF You have the primary stresses there
is no shear on the element.
More Smore
Nailing a Principle Stress or Maximum Shear
Plot your stresses or
Identify your compression
Tension and shear
Get the Radius and
Center of Mohr’s Circle
Get Principle Stresses
And/or Max Shear
Bending Stress in a Beam
Maximum Stress at the outermost fiber
Radius of Curvature of the
bend
Bending of Multi-Material Beams
A Four Step Process
The New Idea!
You begin with the ratio of the Young’s Modulus
Material 1
Material 2
Meanwhile Somewhere Below
D
Darn flying cows
You Next Find the New Neutral Axis
Yes the Neutral Axis has Moved
Resisting Areas Above and Below
The Neutral Axis
(Adjusted for stiffness ie n)
Must be Equal.
Now We Need the Moment of Inertia
of Our Two Component Areas About
the New Neutral Axis
From the Statics Section
Note that the stiffer material has been
Converted to a larger equivalent area
Using the stiffness ratio n
Now Use Your Beam Bending Stress
Formula
Do note that the stress in the stiff
Member is multiplied by the stiffness
ratio
Column Buckling
The load to fail a column by buckling is in
The Mechanics of Materials Section
Trick – effective column
Length varies with how
It is held at the end
The conversion factors for effective column length are in
The Mechanical Engineering Section
The Eccentric Load Problem
Load
Eccentric Loads Break Down
Into two problems
1- An axial load problem – just
Pretend the load is dead center
axial
Offset Distance
2- A bending moment problem – assume
A bending moment = load * offset distance
3- Calculate the results for each problem
Separately
4- Add the results.