Mock FEs

An Extra Credit OptionThese 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 basedTests

• 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 TakingMy FE

Using Computers

You will have a computer key board, a 24 inchScreen, a calculator, a 10 page dry erase boardFor 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 searchableElectronic 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 formsThat you will not memorizeAnd 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%– Your lowest gets dropped so grade is best 24– You can use 2 more FE passes to replace other

homeworks with 100s

I got mine in a box of Cracker Jack

You don’t want to knowWhere 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

The FE Left Me FeelingLike This Too!

Yes - If you pass a lowest score turnsInto 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)

Some Strategic Ideas

The 3 Pass Method

1- Pass one – get all the easy onesYou can do in one step without anyStruggle to find formula’s(on the way through flag those you knowHow to do but might need more time)In the mock exam – dump all the wrongSubject questions

2- Pass two – go back and nail all the onesYou know how to solve but have to searchFormulas and make more steps

3- Pass three – last perhaps 5 minutes –Guess (use common sense narrowing to improveYour odds – Leave no answer undone

The Mission Control Pad

Use one page of your note padTo write yourself notes and tipsAs you make your passes.

What Do I Do With Hard Problems?

Some Problems Look Hard but haveNon-obvious “make it easy” tricks

What is the reaction at A in theX direction?

Some Hard Looking Problems Dump Extra Information on You

Oh Crap

Just What I HadI Mind.

It wants youTo go intoAn involvedThermalStress problem

Last Possibility for Hard ProblemYou are not suppose to beAble to Finish the Test in theAllotted time.

Some problems are there justTo bleed their victims to deathOn time - narrow the field andGuess.

Study Strategy

Don’t CramAim to Gear Up Over an 8Week period

Don’t Freak-OutThe FE Book ContainsMostly dump on information.Only a few things are critical

Practice the FundamentalsUse a good study guide to review basicsAnd spend time doing problems – PaceAnd Discipline.

I crammedLook What Happened

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 toThe test center without rushing

Allow a little relax time when youGet there.

Oh God – I PromiseTo be good if you letMe pass

Typical DistributionGeneral 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 MechanicsOf Materials

More on Thermal Strain Problem

Fifth Page of Mechanics ofMaterials to get CoefficientsOf Thermal Expansion if notGiven.

Thermal Expansion With Constraint Problem

Immovable wall

Immovable wall

The rod would like to expand – but can’tThe result is thermal stress

1- Calculate how much it would expand if thereWere no constraint.

2- Find the force that needs to be applied to reverseThe expansion

3- Use definition of stress to get the stress if theProblem calls for it.

From page 1 of MechanicsOf Materials

From page 1 of MechanicsOf Materials

The Statically Indeterminate Problem

Duplicate forces can cause us to run out of statics equationsBefore 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 theDeformation that would happen if there were only oneSupport.

Of course you know that deformation doesn’t really occurThat way. You now add back enough of the removed forceTo counter the deformation.

This leaves you with one unknown force and one staticEquation.

The Torsion Problem

Version one – Torsion Twists Something

Bottom of Page 4 of Mechanics of Materials

I can’t Look

What about Me?

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 onYour face – Its in the problem.

When its not look at the material propertiesTable on page 5 of Mechanics of MaterialsSection

The Next Torsion Problem isthe find the Shear Stress Version

For a RegularShaft For a thin walled

shaft

How Is Torsional Shear Stress Distributed?

Zero at the center rising linearly to theOutside edge.

The Pressurized Tank Problem

Thick walled cylinder – axial, hoopAnd radial

Page 1 Mechanics of Materials

The Thin Walled CylinderTop of Page 2

HoopStress

AxialStress

Find the Centroid

Just the area weighted averageOf the centroids of the componentAreas.

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 inertiaOf the component areas(formulas at the end of Statics)

Transfer the components to the commonAxis with the Parallel Axis Theorem Add them up.

Smores Circle

State of Stress at One Point Only!

IF You have the primary stresses thereis no shear on the element.

More SmoreNailing a Principle Stress or Maximum Shear

Plot your stresses orIdentify your compressionTension and shear

Get the Radius andCenter of Mohr’s Circle

Get Principle StressesAnd/or Max Shear

Bending Stress in a Beam

Maximum Stress at the outermost fiber

Radius of Curvature of the bend

Bending of Multi-Material BeamsA Four Step Process

D

Darn flying cows

The New Idea! You begin with the ratio of the Young’s Modulus

Meanwhile Somewhere Below

Material 1

Material 2

You Next Find the New Neutral AxisYes the Neutral Axis has Moved

Resisting Areas Above and BelowThe 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

Note that the stiffer material has beenConverted to a larger equivalent areaUsing the stiffness ratio n

From the Statics Section

Now Use Your Beam Bending Stress Formula

Do note that the stress in the stiffMember is multiplied by the stiffnessratio

Column Buckling

The load to fail a column by buckling is inThe Mechanics of Materials Section

Trick – effective columnLength varies with howIt is held at the end

The conversion factors for effective column length are inThe Mechanical Engineering Section

The Eccentric Load ProblemLoad

Offset Distance

Eccentric Loads Break DownInto two problems

1- An axial load problem – justPretend the load is dead centeraxial

2- A bending moment problem – assumeA bending moment = load * offset distance

3- Calculate the results for each problemSeparately

4- Add the results.