Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
MER 312: Dynamics and Kinematics
BY
Abraham Tchako, PhD
Fall 2008
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Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
(L2)
MER 312: Dynamics and Kinematics
TODAYS AGENDACourse organizationCourse ObjectivesExpectationsResourcesIntroductory MaterialDemonstrations
L1
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Course Organization
Schedule:MWF 11:45 am 12:50 pm NWSE 205 (Lecture)Th. 1:55 pm 4:45 pm NWSE 205 (Lab)
Instructor: Abraham Tchako, Ph.D.Room 235 Steinmetz HallTel.: 388-6144Email: [email protected]
Office Hour: MW 10:30 am 11:30 amRoom 235 Steinmetz HallOr by appointment
Textbook: Cleghorn, W. L., Mechanics of Machines, 2005.Oxford University Press
Web Page: http://antipasto.union.edu/~tchakoa/mer312/.
mailto:[email protected]://antipasto.union.edu/~tchakoa/mer312/
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
The principal objectives of this course are:
To develop your understanding of the fundamentals of kinematics and dynamics of mechanisms and machine elements.Gain experience using computer software to facilitate the design and analysis of simple and complex mechanisms.Gain practical working knowledge, through design project, of some basic machine elements such as motors, gears, belts, cam, and common linkages.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
What is expected of you in this course?
You are expected to:- Attend all classes and design project
sections- Check course web page periodically and
regularly.- Do all homework on time - Do all
progress reports of the design project on time
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
What is expected of you in this course?
You are expected to:- Do all hws, projects and present them
in the form prescribed if any.- Be a good team member (design
project) - Start the project when it is handed out. - ALL your work must be your own or
your groups!
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Course Resources & Webpage
ResourcesTextbook:
W. L. Cleghorn, Mechanics of Machines, Oxford University Press, 2005 with CD-ROM.
Interactive 3D and 2D Virtual models. Flux Player to view virtual models Working Model Cam Design computer program Scaled diagrams of mechanisms for solving problems SolidWorks/COSMOS Motion
Lecture Notes onlineCourse Web page
http://www.engineering.union.edu/~tchakoa/mer312/
http://www.engineering.union.edu/~tchakoa/mer312/
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Course Evaluation
Your Graded will be based on:- Assignments,- 3 Exams (2 exams and 1 final), - Lab/Projects and,- QuizzesArrange yourselves in project groups of 3 to 4 by 9/25If not in a group by that date You will be assigned to one
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Mechanical Engineering
AerodynamicsHydrodynamics
Fluid Mechanics
Thermodynamics
KINETICSKINEMATICS
DynamicsStatics Stress Analysis
Solid Mechanics
Introduction
KINEMATICS -
THE STUDY OF MOTIONWITHOUT REGARD TO FORCES
KINETICS -
THE STUDY OF FORCESDUE TO MOTION
DESIGN -
THE CREATION OF SOMETHINGTHAT DIDN'T EXIST BEFORE
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Units are the Bane of an Engineers Existence
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Definitions
Mechanism: a device which transforms motion to some desirable pattern and typically develops very low forces and transmits little power.
Machine: typically contains mechanisms which are designed to provide significant forces and transmit significant power
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Demonstrations
Single-cylinder piston engine
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Definitions
Similarities: They are both combinations of rigid bodies (Links) the relative motion among the rigid bodies are definite.
Differences: Machines transform energy to do work, while mechanisms do not necessarily perform this function.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Commonly Employed Mechanisms
Slider Crank Mechanisms:
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Commonly Employed Mechanisms
Four-Bar Mechanisms:
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Commonly Employed Mechanisms
Belt Drive and Gearing Mechanisms:
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Commonly Employed Mechanisms
Cam Mechanisms:
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Kinematic Chains and Kinematic pairs
Kinematic Chain: is an assemblage of links and kinematic pairs capable of relative motion. The base link is not specified.
Mechanism: a kinematic chain in which at least one link is fixed (the base/ground link) with the purpose of transforming motion.
Kinematic Pairs or Joints: connect the links of the mechanism together.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Links
Link is a rigid body that possesses at least 2 nodes.
Node is an attachment point to other links via joints.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Kinematic Pairs or Joints
Kinematic pair/ joint is a connection between two or more links at their nodes. It allows motion to occur between the links.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Basic Types of Kinematic Pairs or Joints
Turning pair/Pivot is a joint that allows relative turning/rotary motion between two links.
Slider or sliding pair is a joint that allows relative sliding/linear motion between two links.
Rolling pair allows relative rolling motion between two links.
A connection may allow more than one type of relative motions between its links.
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Sample of Kinematics Pairs
Prismatic
Revolute
Screw
1 DOF
Joints
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Sample of Kinematics Pairs
Cylindrical Pin-in-slot
Half joint
2 DOF Joints
Multi-link
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Sample of Kinematics Pairs
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Joints restraint and allow motion between links
Sample of Kinematics Pairs
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Sample Problems for self study
Problem for self study
Identify
(1) Number Elements(2) Number Joints(3) Calculate mobility
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Demonstrations
Single-cylinder piston engine
Union CollegeMechanical Engineering
MER 312: Dynamics and Kinematics (of Mechanisms) / AT
Demonstrations
Upload Mechanism
MER 312: Dynamics and KinematicsCourse OrganizationThe principal objectives of this course are:What is expected of you in this course?What is expected of you in this course?Course Resources & WebpageCourse EvaluationUnits are the Bane of an Engineers ExistenceDefinitionsDemonstrationsDefinitionsLinksDemonstrationsDemonstrations