Physics 482

Acoustics II: Sound and Vibration

Spring 2005

Text: Handouts, journal articles, library reserves

Description

Any sufficiently advanced technology is indistinguishable from magic.
 - Arthur C. Clarke

We will tear off the curtain to understand the magic.  The course will develop from the simplest oscillator to build in increasingly complexity.  The topics, roughly one per week, are:

• 1-dof oscillators, mass-spring-dashpot (MSR) systems, vibration isolation
• Assemblies of lumped-element systems: mechanical, acoustical, and electrical equivalent circuits, loudspeaker design
• Coupled oscillators, multiple-dof systems, modal analysis
  
• Infinite-dof systems: 1-d string, 2-d membrane
• Infinite-dof systems with shear stiffness: 1-d beam, 2-d plate
• Vibration isolation, part II: walls, barriers, transmission and insertion loss
  

Several themes will carry through the term.  To master the material, you should be cognizant of these:

• We model reality with simple structures.
  
• The physics of these simple models is described directly through governing equations.
• The governing equations are amenable to analytic solutions (most from differential equations theory).  Those that aren't are often approached numerically, with computational methods such as finite difference or finite element analysis.
  
• These analytic solutions are often in terms of families of solutions (like modes of a structure), which must be tied back to reality with understanding, and, sometimes, art.
  

Course Resources

Student Performance

Homework Sets 40%

Lab Worksheets 20%

Weekly Updates 10%

Team Presentations (two per term) 20%

Unit Tests 10%

Lab Worksheets.  There will be six opportunities for us to go into the lab (or work on equipment in the classroom).  Each time, you'll have a little worksheet to complete and turn in.  The first part of the worksheet (Prelab Exercise) must be completed prior to coming to class on lab day.  These are due that day in class, or may be turned in the next class day.

Weekly Updates.  These are weekly summaries of the course to help you organize the material.  Turn them in every Monday at the beginning of class.  The format:  An introductory paragraph will explain the big idea(s) from the week.  Then an outline will assemble the items by topic -- this may not be chronological!  Combine the material as you see it, but try to be thorough and well-organized.  Finally, a closing paragraph will discuss applications of the theory, subtle mathematical techniques used, and any other details you'd like to record.  These will be evaluated for both clarity (be concise!) and thoroughness.  In other words, they shouldn't be too short nor too long!  In addition to your grade on these, you may also receive a personal evaluation of your performance in class.

Team Presentations. Twice in the term, groups of three (chosen by the instructor) will make a presentation of how others are deploying this theory in industry or science.  Typically, you and your group will tear apart an article of your choosing, understand what the problem and solution were, and present it to the group.  The deliverables will be a power point presentation, with complete notes, and the presentation to the class.  Your peers will evaluate the presentation, and you will evaluate your own group work.

Unit Tests.  The Unit Tests will be the main vehicle to demonstrate your individual understanding.  These will be completed in class, and will cover roughly two or three homework assignments' worth of material.  These are very concept-oriented, and will be written without book, notes, or other resources.

Course Policies