|
|
The videotaped lectures,
"Basic series in Vibration and Acoustics"
come in four DVDs. The DVDs include a copy of
a program transmitted via satellite in December 1997, featuring
Wayne Tustin.
We thank National Technological University,
Fort Collins, Colorado for the use of this material.
Click here for price and
purchase information
Hour 1
- Introduction to the course
- Purposes and types of environmental
tests, emphasizing vibration and shock
- Introduction to classical sinusoidal
vibration and sound
- Unidirectional (automobile) displacement,
velocity, acceleration
- Sine vibration: displacement, velocity,
acceleration
- Single-degree-of-freedom system,
natural frequency
- Transmissibility, resonance, isolation
- Single-degree-of-freedom demonstration
on shaker
- Critical damping: Army gun recoil
demonstration
- Passive vs. active isolation
- Cantilever beam demonstration on shaker
- Natural frequencies of a cable under
tension, musical instruments, classical beams and plates
- Modal analysis and testing
- Effect of damping
Hour 2
- Sinusoidal vibration and sound measurements
- Linearity; probability
- Instruments: sensors especially
accelerometers, force sensors, microphones
- Readouts; sources of error; six
ratios between force and motion
- Calibration of sensors and systems;
NIST traceability
- Absolute vs. comparison
- Calibration at various temperatures
- Microphone calibration
- Most machinery vibration is complex;
introduction to spectrum analysis
- Time and frequency domains; Fourier
transform
- Multiple frequencies; spectrum analysis;
line spectra
- Videotaped demonstration: sine and
square waves; musical tones
Hour 3
- An early military test specification
- Examples of sinusoidal vibration calculations
- Better understanding resonance
- Stiffness/natural frequency relationship
- More on instrumentation, spectrum
analysis, avoiding measurement errors
Hour 4
- Review of first day; preview of today
- What should we test? When should we
test it? Where should we test it?
- Vibrating platforms; need for multiple
exciters; mechanical shakers not too useful
- Electrohydraulic shaker systems; multi-axis
testing more realistic than single axis
- Electrodynamic shaker systems
- Unwanted shaker motions
- Multi-axis electrodynamic shaker systems;
video clip
- Modal analysis; modal testing with
electrodynamic shakers
- Power amplifiers; current and voltage
demand; harmonic distortion effects on shaker
- Electrodynamic shaker system ratings
- Understanding sinusoidal vibration
test specifications
- Why are we still doing sine tests?
- Shaker controls: older analog and
present digital shaker controls
- Load resonances; antiresonances
- Sine vibration testing; control strategies
Hour 5
- What is random vibration?
- Review of line spectra; extend to
continuous spectra
- Sources (in service) of random vibration
- Random vibration video clip
- No equivalence between random-sine
- Instrumentation for random vibration;
narrow-band spectrum analysis; need for g2/Hz
- Meaning of term RMS
- Earthquakes are random
- Designers: don't stack your resonances!
- Amplitude sampling; probability density
graphs
- DeciBel notation in random vibration
testing
- Fitting test spectra to field data
- Older analog spectrum shapers reviewed;
today's computer controls Introducing Gerry Priebe of Data
Physics Corp.
- Sine signal demonstration; waveform
and histogram
- Random signal demonstration; waveform
and histogram
- Sine and random mixed signals; waveform
and histogram
- Tiny shaker - random vibration demonstration;
beams with accelerometers
- Computer compensates for resonance
characteristics of shaker and of load
- Repeat for swept sine test; mention
of sine on random testing, force limiting
Hour 6
- Vibration test fixtures; function
of fixture; classical fixtures types
- Attempt to keep fixture resonances
above the test frequency range
- Fixture fabrication - most often welded
- Bolted connections - axial loading
- lateral loading
- Mechanical impedance of fixtures; attempt
to match service mounting
- Avoid fixtures overhanging shaker table;
us of head expanders, slip plates
- IEST Recommended Practices on Fixture
Design
- Environmental stress screening (ESS)
and related topics
- Thermal stressing
- Random vibration stressing; multiple-axis
excitation with pneumatic vibrators
- Ford video clip
- Buzz, squeak and rattle (BSR) problems
explained; solutions
- BSR vibration testing
- HASS, HASA, HALT testing; compressing
test time
Click here for price and
purchase information
|
|
|
