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Noise & Vibration Consultants

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Hands-On Modal Testing & Analysis Course

Laboratory Exercise - Modal Test on the Jim Beam:

  • Data Physics Multi-Channel Data Acquisition with the Abacus System

  • PCB Piezotronics Impact Hammer

  • PCB Piezotronics Mini Tri-Axial Accelerometer

  • ME'Scope Modal Software

Exercise Objectives:
Students acquire the modal data set (7 data sets with a total of 99 FRF measurements), import the frequency response functions into the modal package

Acquiring modal data on a Porsche

Modal Test of a Porsche 914 (ok ... a VW 914): .

  • HP 3566A 16 Channel Analyzer

  • APS Model 113 Long Stroke Electro-Dynamic Shaker

  • PCB Piezotronics Model 333A31 Accelerometers

  • PCB Piezotronics Load Cell

  • ME'Scope Modal Software

Exercise Objectives:
Students are asked to setup the test instrumentation, acquire the modal data set, import the frequency response functions into one of the three modal packages listed above, set-up the modal geometry, curve fit the data and animate the mode shapes.

 

Porsche modal - students feel the roll & pitch modes.

Sine Dwell Test of a Porsche 914:

Exercise Objectives:
A sine wave is used the drive the APS Model 113 Long Stroke Electro-Dynamic Shaker at each of the vehicle resonance's identified during the modal test.  The students have the opportunity to get a "hands-on" feel for the suspension modes and the first couple of structural modes.

Evening Session  (Wednesday Night - 8:40 pm):

Laboratory Exercise - Modal Test on a 914:

Exercise Objectives:
The Students setup the transducer, measure the position & angels and the test instrumentation.

 

Evening Session  (Wednesday Night - 9:40 pm):

[The curvature of the Porsche needs some special attention.  What is the transducer orientation and angles & how accurate do we have to be ? I wouldn't ask this guy.]

A discussion on how to calibrate a load cell and impact hammer.

Laboratory Exercise - Impact Hammer Calibration:

  • According to Newton, F = m * a

  • Did he have Hammer Calibration in mind?

  • How do you set up a calibration mass?

  • How does the load cell sensitivity change with tip
    hardness, mass extenders, etc.?

  • RCAL IBASIC Software Application

Disk Drive modal test using a Polytec Laser Vibrometer

Laboratory Exercise - Modal Test of a Disk Drive Chassis:

  • HP 35670A Analyzer

  • Ling electro-dynamic exciter & B&K Load Cell

  • Polytec Laser Vibrometer

  • STAR Modal, CADA-PC & MES'cope Modal Software

Exercise Objectives:
Students are asked to setup the test instrumentation, acquire the modal data set, import the frequency response functions into one of the three modal packages listed above, set-up the modal geometry, curve fit the data and animate the mode shapes.

The unique aspect of this test is that the structural response is measured with a laser vibormeter which sences the surface velocity.  Is the modal response proportional to the real or imaginary part of the frequency response?

Modal test of a Golf Club

Laboratory Exercise - Modal Test of a Golf Club:

  • HP 35670A Analyzer

  • PCB Piezotronics Impact Hammer

  • PCB Piezotronics Accelerometer

  • STAR Modal, CADA-PC & ME'Scope Modal Software

  • RRIT Roving Response Impact Testing, IBASIC Software Application

Exercise Objectives:
Students are asked to setup the test instrumentation, acquire the modal data set, import the frequency response functions into one of the three modal packages listed above, set-up the modal geometry, curve fit the data and animate the mode shapes.

Laboratory Exercise - Modal Test on the Jim Beam:

  • HP 35670A Analyzer

  • PCB Piezotronics Impact Hammer

  • PCB Piezotronics Accelerometer

  • STAR Modal, CADA-PC & ME'Scope Modal Software

  • RRIT Roving Response Impact Testing, IBASIC Software Application

Exercise Objectives:
Students are asked to setup the test instrumentation, acquire the modal data set (approx. 33 measurements), import the frequency response functions into one of the three modal packages listed above, set-up the modal geometry, curve fit the data and animate the mode shapes.

Laboratory Exercise - Modal Test on a Thin Plate:

  • HP 35670A Analyzer

  • PCB Piezotronics Impact Hammer

  • Polytec Laser Vibrometer

  • STAR Modal, CADA-PC & ME'Scope Modal Software

Exercise Objectives:
The Student setup his test plate and the test instrumentation.  A total of 20 FRFs were acquired on a 3" x 5" plate.  The suspended plate was impacted with a miniature impact hammer (Looks like he got a workout.).  The response was acquired in terms of surface velocity with a Fiberoptic Laser.  The frequency response functions were imported into one of the three modal packages.

A well deserved rest!

Evening Session Break (Wednesday Night - 10:30 pm):

  • He finished the pizza and beer.

  • I wonder if he completed his modal test ?

  • [Don't worry Dave, we haven't E-mailed this picture to anyone at your office.  By the way, I asked Hans "not "to give our web address to your wife.  Unfortunately, she called before I spoke with him.  Sorry, Jim]

Evening Session Break (Wednesday Night - 10:00 pm):

  • Another example of a dedicate attendee