SYLLABUS MAE342 Dynamics of Machines (CRN: 12551) Term: Spring 2015 Meeting time & Room: Instructor office, phone and email: Office Hours: TA & Office Hours: MWF 12:00 to 12:50, ESB-E G102 Dr. Victor Mucino, Office ESB-341 Ph. (304) 293-3150, e-mail: vhmucino@mail.wvu.edu T, R, 1:00-2:00 (other times by appointment). Lei Jian, Grad. Student MAE. Office Hours: TBA Textbook: DESIGN OF MACHINERY: An Introduction to the Synthesis and Analysis of Machines and Mechanisms. 5 th Ed. McGraw Hill Book Co. (It comes with a DVD that will be necessary for assignments) Author/ISBN: Robert L. Norton, ISBN 0-07-286447-8 Prerequisites: Supplies/Other: MAE-242 Dynamics and MATH-261 Diff. Equations (Co-Requisite). Drafting kit will be needed, access to the Internet on a PC or laptop, Matlab (or similar) programming skills will be needed. Course Objectives The objective of this course is to provide students with the necessary knowledge on the methods needed to formulate analytical models and to analyze and synthesize machines and mechanisms to perform specific engineering functions. The methods involve analytical, numerical, graphical and computational approaches to establish the relationships between link dimensions, motion characteristics and forces with associated power and work delivery. Basic vibration characteristics of machines and mechanisms will also be addressed. Specifically the objectives are: 1. To model various types of mechanisms 2. To analyze kinematics and dynamic characteristics of machines and mechanisms 3. To synthesize closed loop mechanisms to satisfy specific performance requirements Course Learning Outcomes: Students will be able to develop and demonstrate ABET Outcomes* 1. Mathematical models of mechanisms and machines for kinematic analyses E 2. Conduct Force analysis of mechanisms under static and dynamic loads. E 3. Synthesize mechanisms for specific kinematics and dynamic requirements. E 4. Use of graphical, analytical and computational approaches for the E representation of realistic machines and mechanisms for meaningful analysis and design purposes. 5. Understand physical, professional responsibility and ethical consequences of mechanism failures. F This course effectively supports more ABET Outcomes than those shown in this table, but will provide evidence to support the assessment of ABET outcomes E and F. 1
TOPICS FOR THE COURSE: I INTRODUCTION TO KINEMATICS Basic definitions and descriptive nature of mechanisms and issues related to the kinematic and dynamic modeling and study of mechanisms. Emphasis will be given to the four-bar mechanism, the slider crank mechanism, and the concept of degree of freedom. Concepts of professional responsibility and ethics of mechanism failures will be presented through a case study assignment. II MECHANISM DESIGN PROCESS The stages of the general design process for mechanisms. Emphasis will be placed on mechanism classification, and types of mechanisms with graphic representation of joints for 2D and 3D mechanisms. Introduction to Working Model Software. III GRAPHICAL SYNTHESIS OF MECHANISMS Dimensioning of planar (2D) linkages for function, path and motion generation with practical applications. Illustrations with Working Model Software. IV DISPLACEMENT AND VELOCITY Analytical approaches for the position, displacement and velocity vector analysis of mechanisms. Emphasis will be placed on the relative motion concepts (linear and rotational) applied to the four-bar mechanism, the slider crank mechanisms and their combination. Review of Grashoff s Law for the four-bar mechanisms and extreme positions. Use of graphical, analytical, numerical and computational approaches for position and velocity analysis of general mechanisms. Instantaneous centers of rotation and Kennedy s Theorem. Review of the concept of mechanical advantage. V ACCELERATION ANALYSIS Graphical, analytical and computational methods for the acceleration analysis of four-bar, slider crank and combined mechanisms. Acceleration polygon and vector representation of acceleration of mechanisms. VI VII VIII IX DYNAMICS OF MECHANISMS Force analysis of mechanisms. Inertia forces, kineto-static analysis of mechanisms and the matrix method for force analysis. Review of shaking forces balancing of rotating elements and mechanical vibrations for single and multi-degree of freedom systems. CAM DESIGN Basic cam-follower mechanisms, motion characteristics for flat face and radial roller followers. Graphical and analytical approaches for cam profile synthesis. GEARS AND GEAR TRAINS Gear tooth shape, gear standard parameters, gear contact kinematics. Planetary and differential gear train systems. Power-flow in branching of gear trains. INTRODUCTION TO MECHANICAL VIBRATIONS One degree of freedom damped and undamped, free and forced vibrations, two degrees of freedom and multi-degree of freedom systems. Lagrangian approach to derive the equations of motion for multi-degree of freedom systems. 2
TERM PROJECT Students will develop a project in teams of two (2). The project will be assigned during the second or third week of the course. The project will require students to make use of the computational tools such as MATLAB, EXCEL, etc. A progress report and a final report of professional quality (word processor narrative, computer sketches, engineering calculations, etc.) will be required at the end of the course. The project will be due the last day of classes. CLASS ATTENDANCE POLICY Class attendance contributes significantly to academic success. Students who attend classes regularly tend to earn higher grades and have higher passing rates in courses. Excessive absences may jeopardize students' grades or even their ability to continue in their courses. Students are responsible for missed work and for assignments given during absences. Attendance will be randomly taken. Students with more than 10% absences will be penalized 10% of the final grade. For anticipated special circumstances student must seek instructor s approval. CLASS RULES 1. Professional attitude in class is expected from all students. 2. No cell phones or MP3Players allowed in class, 3. Disruptive behavior in class will not be allowed (that includes reading newspaper, falling asleep, using music players and talking). 4. Assignments must be submitted IN CLASS at the time they are due. (NOT responsible for assignments submitted in mailbox, in the halls or under my office door) 5. Late assignments will be penalized 10% per day. 6. Late assignments will not be accepted after solutions are discussed in class or after one week past due. 7. All assignment problems must be presented on individual pages on plain white paper or engineering pad paper (each page must have DATE and NAME). 8. Missing an exam with no justification will result in a Zero grade for that exam. 9. Completeness, neatness and legibility in assignments, exams and projects are mandatory. Sloppiness will be penalized at instructor s discretion. GRADING WEIGHT Assignments & Quizzes 30% Project* 20% Exams (2) 30% Final Exam 20% * Peer evaluation will be factored in the individual grade for project GRADING SCHEDULE Grade is assigned based on performance, NOT on effort. Project is assessed based on overall quality of document and engineering considerations as well as on relative comparison with the rest of the class. 3
90 100 A 80 89 B 70 79 C 60 69 D 0 59 F IMPORTANT DATES January 12, 2015 January 16, 2015 January 19, 2015 February 16, 2015 February 27, 2015 March 6, 2015 March 18, 2015 March 20, 2015 March 21-29, 2015 April 3, 2015 April 30, 2015 May 1, 2015 May 4-9, 2015 May 6, 1015 May 15, 2015 First Day of Classes Last day to add/drop courses Martin Luther King Day (recess Exam 1 (Monday) Mid Semester Midterm Reports Due Exam 2 (Wednesday) Last day to drop a class Spring Recess Friday before Easter (recess) Last Day to withdraw from the University Last day of class Final Examination Week Final Exam 3:00 to 5:00 pm (Wednesday) Commencement STATEMENT ON ACADEMIC INTEGRITY The integrity of the classes offered by any academic institution solidifies the foundation of its mission and cannot be sacrificed to expediency, ignorance, or blatant fraud. Therefore, I will enforce rigorous standards of academic integrity in all aspects and assignments of this course. For the detailed policy of West Virginia University regarding the definitions of acts considered to fall under academic dishonesty and possible ensuing sanctions, please see the Student Conduct Code at http://www.arc.wvu.edu/rightsc.html. Should you have any questions about possibly improper research citations or references, or any other activity that may be interpreted as an attempt at academic dishonesty, please see me before the assignment is due to discuss the matter. INCLUSIVITY STATEMENT The West Virginia University community is committed to creating and fostering a positive learning and working environment based on open communication, mutual respect, and inclusion. If you are a person with a disability and anticipate needing any type of accommodation in order to participate in this class, please advise me and make appropriate arrangements with the Office of Accessibility Services (293-6700). For more information on West Virginia University's Diversity, Equity, and Inclusion initiatives, please see http://diversity.wvu.edu 4
MAE342, Assignment 1, Due Wednesday, January 21, 2015 All assignment problems must be presented on individual pages on plain white paper or engineering pad paper (each page must have DATE and NAME) and are strictly individual. 1. Reading Assignment. Read Textbook Chapter 1 (This chapter will not be covered in class) and write a brief summary of the chapter (one page) 2. Professional Responsibility and Ethics. Access and read the Professional Engineer s Code of Ethics, ( http://www.nspe.org/resources/ethics/code-ethics), then Conduct an Internet search to find at least one case of a reported accident (in the public domain) caused by the failure of a mechanism. a) Was the failure caused by (choose one): i. Mechanism malfunction (describe it) ii. Operator malfunction (describe it) iii. Inappropriate maintenance (describe it) b) Who was at fault? Discuss in your own words if the engineer in charge of design or in charge of production or in charge of service was ethically responsible or not and why? i. The user (why?) ii. The product maker (why?) iii. The design engineer (why?) iv. The service technician (why?) c) What were the consequences? i. Material losses (describe it) ii. Injuries or life loss (describe it) iii. Other (??) d) Describe how this accident could have been prevented? e) Provide the internet reference link and a print of the front page. 3. Solve Text Problems: Pr. 2-1 Letters a, j, and n Pr. 2-12 Letters a and d Pr. 2-24 (Sketch the mechanisms, label the joints, the type of joints also label the links and indicate their type). 5