SEMINARS
related to Vibration Analysis offered by Technical Associates
of Charlotte
Applied
Modal & Operating Deflection Shape Analysis |
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Fee for Applied Modal & Operating Deflection Shape
Analysis: $1995
Add a Pocket Vibration Diagnostic Handbook for $49.
Delivered to you at the Seminar.
APPLIED
MODAL & OPERATING DEFLECTION SHAPE ANALYSIS
This
4-1/2 day course provides a basic understanding on how to use
Experimental Modal Analysis (EMA) and Operating Deflection Shape
Analysis (ODS).
The focus of this class is on applying these powerful diagnostic
tools on real-world machinery and structures rather than expending
class time on deriving high-level mathematical formulas (a background
in differential equations and Laplace transforms will aid the
student in comprehending concepts taught, but is not required
today even to apply these tools to complex mechanisms & structures
since such mathematics is now taken care of by the software).
Knowing
how to employ ODS and Modal methods have become particularly important
today now that Resonance is now one of the leading (and often,
The Leading) problems to which today’s machinery is subjected.
That
is, the emphasis in this class will be on how to properly perform
ODS and EMA measurements, how to interpret their results from
computer animations, and how to formulate meaningful recommended
corrective actions required to resolve problem conditions found.
The
students are provided with structural models of plant machinery
to generate and import Experimental Modal and Operating Deflection
Shape analysis measurements, and to create machinery animations.
Students are then given an overview on how to: Establish a Project;
Create a Structure; Import Data; Interpret data (ODS, ODS FRF,
and Modal); accomplish Modal Analysis Curve Fitting; and employ
Structural Dynamics Modifications (SDM) needed to predict the
effect of modifications within the model before such modifications
are fabricated and put onto place.
However, the focal point of this class is not to learn how to
use all the capabilities of an excellent software package (ME’scopeVES),
but instead on how to simplify what formerly were complex methodologies
making them practical and demonstrating how these powerful ODS
and Modal analysis tools can be Applied on machinery and support
frame/foundation problems they encounter on a daily basis.
Notebook computer with Windows 2000 or Windows XP is required
for loading of ME'scope Demo Software Package.
| APPLIED
MODAL & OPERATING DEFLECTION SHAPE ANALYSIS AGENDA |
Introduction
and Course Overview
- Definitions
of Experimental Modal & Operating Deflection Shape
Analysis
- Terminology
of Modal and Operating Deflection Shape Analysis
- Instrument,
Transducer & Software Requirements
for Modal Analysis
- How
Modal Analysis Differs from Operating Deflection Shape
Analysis (ODS)
- General
Modal and Operating Deflection Shape Analysis Test Methods
- What
will Modal Analysis Tell You about the Machine and/or
Structure Tested?
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Definitions
- Natural
Frequency, Critical Speed & Resonance
- The
Resonance Phenomenon
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Single
Channel “Bump” Testing With a Variety of FFT Analyzers
- Single
Channel FFT and Time Waveform Measurement
- Recommended
Specific Measurement Setups on Various Analyzers
- Importance
of Proper Triggering
- Phase
Behavior Below, At, & Above Resonance
- Probable
Natural Frequencies
- Background
Forcing Frequencies
- Corrupted
Data - How to Detect & Correct
- Hammer
Type and Tip Hardness - Effect on Excited Frequencies
- Limitations
of Single Channel Bump Tests
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Operating
Deflection Shape Analysis (ODS)
- Definition
of ODS Analysis & Review of its Applications
- Self-Induced
Motions of Machinery
- Defining
“How Much” Motion Present
- Defining
“Time-Varying” Motions
- Resonant
or Non-Resonant Responses
- Animating
The Vibrating “Shape”
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ODS
Rules of Thumb
- Determining
Anticipated Forcing Frequency Amplitudes & Dominant
Directions
- Using
Single Channel Transducer & Phase Reference
- Limitations
of Single Channel ODS Measurements
- Using
the Two Channel Method - Reference & Roving Transducer
- Determining
the Optimum Locations & Direction for the Roving Transducer
- Getting
Repeatable Measurements
- Using
Velocity to Obtain Best Frequency Response for Most Problems
- Determining
When to Use Other Vibration Parameters
- Setting
the Optimum Frequency Range for Specific Problems
- Setting
Optimum Frequency Resolution
- Reducing
Spectral Leakage by Choosing Best Window
- Specifying
the Required Number of Measurement Points & Directions
- Checking
for Reasonable Animation Motion
- Adjusting
for Varying Time & Load
- Keeping
Accurate Records of Locations & Measurement Directions
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ODS
Demonstrations
- Demonstration
of Optimum Techniques Taught
- Use
of Instruments from Various Vendors
- Animating
ODS Computer Model
- Interpreting
ODS Animation Results
- Development
of Required Corrective Actions
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ODS
Case Studies
- Excessive
Flexure on a Large Scrubber Fan at 3X Fan RPM
- Structural
Weakness & Flexure on a Paper Machine Support Frame
- Misalignment,
Excessive Frame Flexure & Ineffective Isolators on
a Process Fan
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Experimental
Modal Analysis (EMA)
- Definition
of Modal Analysis & Review of its Applications
- Design
Optimization
- Diagnostics
on a Variety of Machine Types & Structures
- Troubleshooting
Specific Problems
- Confirming
When Resonance Exists & What Component is Resonant
- Condition
Monitoring Program Enhancement via Modal Analysis
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Mode
Shapes
- Definition
of Mode Shapes & Importance in Resolving Resonance
Problems
- Mode
Shapes of Simple Machines & Structures
- Mode
Shapes of More Complex Machines & Structures
- Mode
Shapes Types - Rigid Body, Bending & Torsional Modes
- Unique
Mode Shape & Damping for Each Excited Natural Frequency
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Modal
Analysis Requirements
- Overview
of Mathematics & Concepts Behind Modal Analysis
- Multi-channel
Analyzers - Spectrum Analyzers or Certain Data Collectors
- Modal
Analysis Software Available
- Structural
Modification Software
- Excitation
Instruments - Impulse Force Hammers, Shakers, etc.
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Frequency
Response Functions (FRF's) & Related Topics
- Definition
of FRF's
- Types
of FRF's (Dynamic Compliance, Dynamic Stiffness, Mobility,
Impedance, Accelerance & Effective Mass)
- Choice
of Proper FRF Type for Specific Machine or Structure
- Damping
– Real vs. Imaginary
- Use
of Real or Imaginary Component forPlotting
Mode Shapes
- Coherence
Function - Definition and Importance of Coherence on Ensuring
Quality Modal Analysis Results
- Cross
Channel Phase Measurements
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Modal
Analysis Rules of Thumb
- Acquiring
Baseline Data with & without Machine Running
- Setting
Proper Frequency Range, #Lines & #Averages for Modal
Measurements
- Using
Proper Window
- Using
Proper Excitation Method to Display All Modes of Interest
- Viewing
Both the Input & the Response Time Waveform
- Using
Exponential Decay Window
- Checking
Coherence Function at FRF Peaks to Determine Measurement
Quality
- Determining
Required #Measurement Points & Directions
- Using
Force Window to Reduce Measurement Noise
- Accurate
Curve Fitting
- Keeping
Accurate Records of Locations & Measurement Directions
- Animating
Modal Analysis Computer Model
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Modal
Analysis Demonstrations on Real Structures & Machines
- Comparison
of Results From Instruments Available Today
- Demonstration
of Optimum Techniques Taught
- Frequency
Response Functions
- Modal
Damping
- Mode
Shapes
- Interpreting
Modal Animation Results
- Development
of Required Corrective Actions
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Modal
Analysis Case Studies
- Turbine
Foundation & Bearing Pedestal Resonances
Driving an ID Fan
- Detection
of Cracks on Large Gearbox due to Operation Near Resonance
- Resonance
Detection on the Frame of a Belt-Driven Blower
- Resonance
on a Paper Machine Slitter Frame
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Prerequisites
- Students
should have 4 to 8 years vibration spectrum analysis experience.
- Prior
formal vibration training & experience with phase
analysis and spectral analysis, plus exposure to natural
frequency testing is recommended in order to allow the
student to become proficient with the application of Modal
Analysis & Operating Deflection Shape Analysis covered
within this 4-day seminar.
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