Module Content:

Module Reading, Problems, and Demo:

MAE 2310 Str. of Materials © E. J. Berger, 2010 1- 1

Module 1: WelcomeJanuary 20, 2010

1. Strength of materials, the follow-on course in the engineering mechanics sequence which started with Statics, provides us with tools to determine key structural engineering response quantities like stress, deflection, and failure.2. Our course policies are similar to those from last semester, with a few small modifications based upon your input.3. This semester, you (yes, you) will be empowered to an even greater degree to control your educational experience.

Reading: Chapter 1Problems: statics review, including FBDsDemo: noneTechnology: http://pages.shanti.virginia.edu/som2010

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Administrative Details• professor: E. Berger (A-122 Thornton Hall, berger@virginia.edu)

• TA: Mr. Anthony Darmiento (MS candidate in ME, ad8u@virginia.edu)

• office hours and problem sessions details are TBD based upon your schedule

• meeting time and location: MWF 12-12.50, MEC 339

• about the course:

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Civil Engineering MAE 2310 - Strength of Materials

Stress and strain definitions: Normal stress and strain, thermal strain, shear stress, shear strain; transformations of stress and strain; Mohr’s circle for plane stress and strain; stresses due to combined loading; axially loaded members; torsion of circular and thin-walled closed sections; deformation, strains and stresses in beams; deflections of beams; stability of columns; and energy concepts in mechanics. Cross-listed as CE 231. (Y)

Prerequisites & Notes Prerequisite: MAE 230, APMA 212.

Credits: 4

This Course information is from the Undergraduate Record 2007-2008.

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Course Policies

• we follow the Honor Code, and the syllabus contains the SEAS-recommended wording (and some student contact information); all exams are pledged, homework assignments are not

• we will use the course blog more than Collab, and I encourage you to sign up for a login so that you can post comments to the blog

• quizzes will be announced at least one class period in advance

• homework submissions must be in my hand at 12 noon (i.e., the BEGINNING of the class period) on the due date

• excused absence does NOT NECESSARILY mean excused from work

• grade appeals must be submitted in writing within 1 week of the assignment return date for consideration

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Course Grading

• graded assignments:

• HW problem sets: about 10 assignments total (15%)

• blog points: details to be distributed soon (5%)

• quizzes (10%): about 5 total

• exams: 3 midterms (15% each), 1 final (25%)

• attendance, participation, etc.: not explicitly part of the grade, but always useful...

• extra credit available...

• for problem solutions submitted and posted on the blog (this semester, ONLY electronic submissions will be accepted, and only the first 2 neat, correct, concise solutions received will be awarded credit)

• each extra solution is worth 1/4 of a homework

• excellent/useful/insightful commentary posted on the blog will also result in extra credit

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Consultation and Getting Help• your first step is always: come to class, work hard and

try to understand, perhaps even consult some friends, and after due diligence...

• your next step is to come see me: send email, visit during office hours, or make an appointment (phone is usually NOT the best way to reach me)

• other options: buy study guides such as the Schaum’s outline listed on the syllabus, pay a tutor

• friendly advice: join a study group of at least 2-3 people (including students from the other section), if not more; alot of great learning takes place in a collaborative environment like a study group

• more friendly advice: take advantage of review sessions and problem sessions--we will do these periodically and announce times and location in advance

• we will also link to lots on online content in support of the class

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Technology Content• how do we use these notes? (I’m not sure, actually, can you tell me?)

• a summary:

• blogging: we will use the course blog as a way to communicate--I encourage all of you to get an account and start hacking (subscribe!)

• podcasts: I will be podcasting all lecture modules and posting them on the blog; this also includes video problem solutions and tutorials

• video solutions: from the publisher’s website, as in Statics

• Arcade: a fun visualization tool and simulator for structures that we will see and use toward the middle of the semester

• Collab: we will occasionally do some surveys, and we will use the gradebook features of Collab; otherwise we will use the course blog

• email: the usual

• a request: the success of some of this technology relies upon you participating, meaning you should work this into your DAILY study routine--check the RSS feeds, review the podcasts, post your course questions as comments on the blog, use email to communicate, etc.

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Course Objectives and Outcomes

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1. Understand the stresses, strains, and deformation response of elastic solids in the presence of external loading.Outcomes:

a. define shear and normal stresses and strainsb. understand the meaning and use of stress – strain diagramsc. define elastic modulus, shear modulus, and Poisson’s ratiod. describe St. Venant’s Principlee. identify a state of plane stressf. understand the concept of stress transformation

2. Calculate stresses within an elastic solid subject to individual and combined external loading.Outcomes:

a. calculate average normal stress and average shear stressb. calculate deflection and reactions for statically determinate and indeterminate:

• axially loaded bars• torsionally loaded circular bars

c. construct shear and bending moment diagrams for beams subject to bending moments and transverse shear loadsd. calculate the normal stress and strain distributions in symmetric beams under pure bendinge. calculate the shear stress distribution in a built up beam subject to shear loadsf. calculate the deflection of beams from the moment – curvature relationshipg. calculate the stress at a point using superposition for the case of simple combined loadings

3. Transform the state of stress in one coordinate system to another.Outcomes:

a. construct a Mohr’s circle diagram from a given state of plane stressb. understand the concept of principle stresses and planesc. calculate (from the stress transformation equations or Mohr’s circle) the principle stresses for plane stressd. calculate the maximum in-plane and out-of-plane shear stress for plane stress

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Course Objectives and Outcomes

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1. Understand the stresses, strains, and deformation response of elastic solids in the presence of external loading.Outcomes:

a. define shear and normal stresses and strainsb. understand the meaning and use of stress – strain diagramsc. define elastic modulus, shear modulus, and Poisson’s ratiod. describe St. Venant’s Principlee. identify a state of plane stressf. understand the concept of stress transformation

2. Calculate stresses within an elastic solid subject to individual and combined external loading.Outcomes:

a. calculate average normal stress and average shear stressb. calculate deflection and reactions for statically determinate and indeterminate:

• axially loaded bars• torsionally loaded circular bars

c. construct shear and bending moment diagrams for beams subject to bending moments and transverse shear loadsd. calculate the normal stress and strain distributions in symmetric beams under pure bendinge. calculate the shear stress distribution in a built up beam subject to shear loadsf. calculate the deflection of beams from the moment – curvature relationshipg. calculate the stress at a point using superposition for the case of simple combined loadings

3. Transform the state of stress in one coordinate system to another.Outcomes:

a. construct a Mohr’s circle diagram from a given state of plane stressb. understand the concept of principle stresses and planesc. calculate (from the stress transformation equations or Mohr’s circle) the principle stresses for plane stressd. calculate the maximum in-plane and out-of-plane shear stress for plane stress

FBDs, method of sections,internal forces, V&M, moment of inertia

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

The Course Blog• course information and

announcements

• threaded discussions

• media home

• link to outside sources

• categories:

• announcements

• homework

• exams

• The Explainer

• where?

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http://pages.shanti.virginia.edu/som2010

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

The Course Blog• course information and

announcements

• threaded discussions

• media home

• link to outside sources

• categories:

• announcements

• homework

• exams

• The Explainer

• where?

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http://pages.shanti.virginia.edu/som2010

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Lecture Podcast Content• the lectures are designed to contain the “static” course

content

• you can download and view these at your leisure

• the “dynamic” course content will be presented live in lecture, and NOT recorded

• the class period breakdown will usually be:

• ~30 minutes of recorded material which sets up the concepts, theories and applications

• ~20 minutes of NOT recorded material which includes physical demos, software usage, and collaborative problem solving

• we will (again) try some pre-lectures, in which I record the lecture module ahead of time, you watch it, then during the class meeting we do 100% collaborative problem solving

• obviously this only works if you actually view the modules ahead of time...

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MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Video Problem Solutions• these Quicktime videos show complete

solutions to problems from our text, including narration and discussion

• they show several useful things:

• the solution, with all math

• the steps in the solution, including “what to watch out for”

• good problem solving technique

• relationships between this problem and others that we have solved

• the spoken word adds great value above the usual “static” written solution on the page

• download and use...you won’t regret it

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don’t forget...the companion website which has 100 videos to accompany the course!

MAE 2310 Str. of Materials © E. J. Berger, 2010 1-

Concept: Strength of Materials• from Hibbeler (p. 3): “Strength of materials is a branch of mechanics that studies the relationships between

external loads applied to a deformable body and the intensity of internal forces acting within the body.”

• Mechanics: (engineering or applied) mechanics is the branch of physics concerned with the analysis of the action of forces on matter or material systems (www.answers.com)

• external loads: forces, pressures, etc. exerted on a body by external means, including point loads, moments, torques, pressures, as well as body forces due to gravity

• deformable body: an elastic body which is NOT rigid (i.e., can deform or change shape)

• internal forces: the forces acting within a structure that react against the external loads (e.g., shear force or bending moment)

• intensity of internal forces: intensity is a way of expressing the (internal) force per unit area; we will come to know this by a much easier name “stress”

• why is stress important?

• essentially all theories of “failure” are related to the stress experienced by a structure

• stress is a physical quantity which can be compared with a fundamental material property (“strength”) to determine whether/when a structure will fail

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