Download F2014 week1.1 intro plus scalars vectors and more Slides Mechanical Engineering in PDF only on Docsity!
E n g G 1 3 0 :
E n g i n e e r i n g M e c h a n i c s
Lecture Section A 1
Sept 20 14 – Dec 20 14
Dr. Michael Hendry
Note on Copyright: These course notes contain figures from the course text, Hibbeler (2010), “Engineering Mechanics, 1 3 th edition in SI Units”, published by Pearson Education South Ltd., Singapore. The notes are posted on a secure web server accessed through ID and password at the University of Alberta, and are not intended for distribution beyond the Engineering Statics (Eng G 130) class. Further distribution or uses may infringe copyright.
Eng G 130: Engineering Mechanics Fall 20 14 Page 1 INSTRUCTOR INFORMATION Dr. Hendry Office: 3 -‐074 Markin/CNRL Natural Resources Engineering Facility Office Hours: Tuesday at 2:00 pm – 3: 0 0 pm Thursday at 2:00 pm – 3: 30 pm ( email to schedule meetings outside these hours ). TEACHING ASSISTANTS TBA HELP CENTRE Staffed by Teaching Assistants. Purpose is to provide opportunity for students to get additional help with course work. Location: NREF 2-‐ 022 Hours of Operation: Monday 10:00 -‐ 16: Tuesday 12:00 -‐ 16: Wednesday 12:00 -‐ 16: Thursday 12:00 -‐ 14 : Friday 12:00 -‐ 14 :
Eng G 130: Engineering Mechanics Fall 20 14 Page 3
- Link to Mastering Engineering
- Calculator policy
- etc. A1 section has information specifically for this section :
- Instructor information
- Lecture Notes
- Handouts Get to it from a link at the top-‐right on www.ualberta.ca
Eng G 130: Engineering Mechanics Fall 20 14 Page 4 TEXT BOOK Hibbeler (201 3 ), “Engineering Mechanics, Statics, 13 th edition in SI Units” MARK DISTRIBUTION Paper Assignments (completed at home) 3% Mastering Engineering Assignments 3% Laboratories 9% Mid-‐term Exam 35% Final Exam 50% 100%
Eng G 130: Engineering Mechanics Fall 20 14 Page 6 MASTERING ENGINEERING ASSIGNMENTS MasteringEngineering (http://www.MasteringEngineering.com) provides online, tutorial help with the course. It is created by the publisher of your textbook (commonly called M-‐E for short). NOTE: Mastering Engineering is mandatory. Each week, three of your six assignment questions are written and three are completed in Mastering Engineering. I recommend that you complete ALL Mastering Engineering questions on paper and then enter your answers into the computer. Sign up using Course ID:
- If you purchase a textbook package from the bookstore this will also contain the resources for your EN PH 131 course on Dynamics. Make sure that to keep the Mastering Engineering access card in a safe place as it will be used in your EN PH 131 course with winter. DO NOT register your Dynamics access code until you have attended the first class of EN PH 131 in the winter as it is only valid for one year after registration. You will only need to register the Statics access code for ENGG 130 this term.
- If you choose to buy access to Mastering Engineering separately please note that you CANNOT buy access online through the Mastering Engineering website for the correct SI version of the Statics textbook. The only place that you can purchase an access code standalone is at the special services desk in the UAlberta bookstore.
Eng G 130: Engineering Mechanics Fall 20 14 Page 7
- If you have any registering issues or have technical questions you should contact Pearson support through the 24/7 Chat Support or by calling Pearson Phone Support during designated hours. If Pearson Support is unable to resolve your issue, ensure that you ask for an incident number. You can provide this incident number to your instructor and they can assist you but they will not be able to address your issues without this incident#.
- You must use the correct Course ID to ensure you get credit the assignments you complete.
- Program will not accept late assignments. (First completed by ) LABORATORIES
- The two-‐hour laboratories are held every week (First lab ).
- The laboratories are problem-‐solving session, not experiments.
- You will be provided with questions to solve. You may work on these in groups and with whatever resources you can bring. Your work must be original (no copying).
- You must attend the section you are enrolled in to get credit.
- You must hand in your laboratories at the end of the session.
- All work must be done on engineering paper.
Eng G 130: Engineering Mechanics Fall 20 14 Page 9 ENG G 130 TOPICS
1. Introduction to Engineering Mechanics
2. Scalars and Vectors
3. Advanced Vectors
4. Particle Equilibrium
5. Moments
6. Couples, Equivalent Systems and Distributed Loading
7. Rigid Body Equilibrium
8. Trusses
9. Frames and Machines
10. Shear and Moment Equations and Diagrams
11. Dry Friction and Wedges
12. Centre of Gravity and Centroid
13. Moment of Inertia
Eng G 130: Engineering Mechanics Fall 20 14 Page 10 1. INTRODUCTION TO ENGINEERING MECHANICS OVERVIEW OF LESSON
- Definitions & Examples: Engineering Mechanics
- Solving Engineering Problems 1.1 What is Engineering Mechanics? ENGINEERING : The application of the principles of science to the solution of practical problems. MECHANICS : A branch of science that deals with the equilibrium of bodies under the action of forces. Application of Engineering Mechanics principles is needed in all engineering “disciplines”.
Eng G 130: Engineering Mechanics Fall 20 14 Page 12 1 .2 Branches of Engineering Mechanics Rigid Body Mechanics: Bodies are assumed not to change shape. That is, the distance between any two points, on a rigid body, remains constant. For example, in analyzing a bridge, the change in shape of the members is so small compared to the dimensions of the bridge itself, that they can hardly be detected by the naked eye. Therefore it makes sense that for certain types of calculations, such changes can be neglected (i.e. assumed to be zero). Rigid body mechanics is sub-‐divided into two areas: STATICS: Deals with the equilibrium of bodies at rest or moving with constant velocity (i.e. zero acceleration). This is the subject of EngG 130****. DYNAMICS: Deals with the motion of bodies that are accelerating. This is the subject of EnPh 131.
Eng G 130: Engineering Mechanics Fall 20 14 Page 13 The other areas of Engineering Mechanics are: Deformable Body Mechanics: This area deals with solid bodies, as in rigid body mechanics, except consideration is given to how the bodies deform. Thus it is necessary to take into account the behaviour of the material, since different materials will behave differently under the same load (ie. steel bridge versus a rubber bridge) Fluid Mechanics: This field deals with the motion of fluids (including gases). Sub-‐ disciplines include, for example, hydrodynamics and aerodynamics.
In Eng G 130 :
We focus on Rigid Body Mechanics for the Static Condition. Thus, our problems will all obey Newton’s 3 Laws of Motion:
Eng G 130: Engineering Mechanics Fall 20 14 Page 15 1 .4 Steps Involved in Problem Solving Let’s look at the problem solving steps in more detail….. STEP 1 : Problem formulation Ask yourself:
- What do you know?
- What do you want to find?
- Which factors are significant or relevant; which are not?
Eng G 130: Engineering Mechanics Fall 20 14 Page 16 So, what should you do?:
- Draw a diagram!!!
- Tabulate data
- Select appropriate idealizations o Rigid bodies, frictionless pulleys, support fixity… STEP 2 : Select governing scientific principles Examples:
- Newton's laws
- Empirical relations determined from experiment How does this help?
- You can identify the appropriate equations, and then identify known & unknown quantities.
- Based on the equations, you determine whether the equation-‐to-‐ unknown ratio will yield a unique solution. STEP 3 : Solve the governing equations for the unknowns How to solve?
- Algebra, calculus, statistics, graphics, etc.
- May need to use a computer. In this course:
Eng G 130: Engineering Mechanics Fall 20 14 Page 18
- Alternate solution techniques?
- Methods available to estimate the answer? 1 .6 Other Solution Hints See the text (Chapter 1), course website, and handouts:
- Required format for solutions;
- Units and unit conversions;
- Engineering Notation; and,
- Rounding off for Numbers.
Eng G 130: Engineering Mechanics Fall 20 14 Page 19
2. SCALARS AND VECTORS OVERVIEW OF LESSON In this section of the course, vectors are critical. Major topics include: - Differences between Scalar and Vector quantities, and differences in notation; - Expression of 2-‐D and 3-‐D vectors in Cartesian Vector Notation (CVN); - Calculation of the magnitude and direction of 2-‐D or 3-‐D vectors when expressed in CVN or otherwise; - Performing vector addition and subtraction using graphical techniques, trigonometry relationships, and by decomposing vectors into components; - Calculation of Position Vectors or coordinate locations based on geometric criteria; - Calculation of components of a vector in specified directions; and, - Use of the Dot Product for vectors in general, but especially for solution of vector component problems.
