Overview

Description

Specifications

Modules

Buzz-o-sonic is a nondestructive testing system designed to measure the elastic and damping properties of materials using the Impulse Excitation Technique or Ping Test1

 

The impulse excitation technique is described here and in ASTM E1876 and C1259 - see References

 

The Buzz-o-sonic system consists of software and hardware components that implement the impulse excitation technique as follows:

 

1. A test piece or product is tapped lightly with a special hammer causing a standing wave to be generated in the solid

2. The resulting vibration (sound) is captured by a microphone attached to a PC running the Buzz-o-sonic software

3. The sound is analyzed using a Fast Fourier Transform (FFT) algorithm

4. The waveform and power or frequency spectrum are displayed from which the resonant frequencies are determined

5. The resonant frequencies are used to determine the elastic properties

6. The Young's modulus, shear modulus, Poisson's ratio, sound and shear velocities are calculated from the known mass and dimensions of the solid

7. The damping properties - internal friction (Q-1) - are calculated using two methods:

 i) logarithmic decrement method (derived from best fit to the waveform envelope - mean squared error of best fit also reported)

ii) half-peak bandwidth method (derived from width of peak in spectrum at half-amplitude - error tolerance also reported)

 

Certified and/or calibrated hardware is used (microphone, signal conditioner, Data Acquisition Card...)

 

A pre-tested aluminum rectangular bar standard is included

 

Buzz-o-sonic has built in algorithms to determine the elastic properties for standard shapes such as discs, rectangular bars, and cylinders; as described in ASTM E1876 and C1259.  Non-standard shapes can also be tested, such as: grinding/cutting wheels, square plates, annular plates (perforated discs), rings, tubes, and bone-shaped tensile bars. Other shapes can be tested. Contact us for more information.

 

A Microsoft Excel® workbook is also included to perform similar calculations. This is better suited for testing many samples. Buzz-o-sonic can communicate directly with the special workbook or any Excel workbook. Typically, the user sends the frequency measurement of interest to the workbook. The frequency can also be sent via RS232 to other instruments by using a special Frequency Broadcaster module.

 

A wide range of sample sizes can be measured: samples from 10 mm in length up to several meters; and thicknesses down to 0.1 mm

 

Buzz-o-sonic can be used to measure very large or small/thin samples that would be very difficult to measure by any other means such as ultrasonic or forced resonance vibration methods

 

The modular design makes it the most flexible and expandable state-of-the-art system available. For example, the QC module allows waveform and spectrum data to be stored and then retrieved as control data from a database of production parts. Control charts with upper and lower control limits can be used to qualify production pieces with simple pass/fail criteria. Several other modules are available and included; custom modules can be added upon request.

 

We supply all that you need to perform the test - Contact us for more details

1The impulse excitation technique is also known as:

 

impulse excitation of vibration

resonant vibration

impact acoustic resonance

ping test

eigen frequency method

Waveform and Sound Input

Sample Rate:

Maximum Time Sample:

Maximum Time Offset:

250 kHz at 16 bit resolution

~1 s (@ 1 Hz resolution)

0.5 s (@ 1Hz resolution)

Power/Frequency Spectrum

Measurement Frequency Range:

Measurement Frequency Resolution:

Measurement Frequency Precision

Window Functions:

Y-scale:

20 Hz - 100 kHz

<1 Hz (alternative user options for 10 Hz and 100 Hz)

0.1 Hz (alternative user option of 1Hz)

Square, Response, Hanning, Triangle, Hamming, Flat Top, Blackman

Amplitude (% fsd), Power (% fsd), Power (dB)

Samples

Materials:

Minimum Sizes:

Maximum Sizes:

Standard Shapes:

Non-standard Shapes:

Any elastic material: metals, ceramics, polymers, composites, coatings...

minimum height ~ 0.1 mm, minimum length/diameter ~ 10 mm

no limit - may need special impulse tool(s) for large, low frequency samples

Rectangular bars, cylinders, and discs

Grinding/Cutting Wheels, Square Plates, Annular Plates, Tubes, Rings, Bone-shaped Tensile Bars

Note: non-isotropic materials can be tested, but only isotropic materials comply with ASTM E1876 and C1259

Elastic Constants Module

Calculate Young's modulus, shear modulus, and Poisson's ratio*

for standard shapes (rectangular bars, cylinders, discs) as per ASTM E1876 and C1259

for non-standard shapes (grinding/cut-off wheels, square plates, annular plates, tubes, rings, bone-shaped tensile bars)

Calculate sound velocity and shear velocity

Estimate resonant frequencies

estimate resonant frequencies from known elastic and physical properties

display estimated resonant frequencies on frequency or power spectrum

 

* Calculations require entering of dimensions plus mass or bulk density of the test sample. These properties along with the calculated elastic properties can be saved with the waveform and spectrum data in a National Instruments' TDM  (Technical Data  Management) or TDMS (Technical Data  Management Streaming) file. These files can be opened using Buzz-o-sonic or any other application that can read TDM/TDMS files such as Diadem or Excel with the TDM Add-In. Note: the resonant frequency is sent to the Elastic Constants module automatically from Buzz-o-sonic

QC Module

Uses historic data to define pass/fail criteria

store resonant frequency, internal friction, and elastic constants data in a TDM/TDMS database

display results in control charts (upper and lower control limits),  histograms, and LED gauges

Store waveform and spectrum data as control data

estimate resonant frequencies from known elastic and physical properties

display estimated resonant frequencies on frequency or power spectrum

Retrieve stored data from a TDM(S) database

test results from production samples can be retrieved from a list of parts

 

 

Spectrogram Module

Plots frequency-time data

useful for troubleshooting in production

use as a QC tool

 

 

Custom Modules

Custom modules can be added on request

Example: a client requested that the resonant frequency be broadcast from Buzz-o-sonic to a shop-floor indicator via an RS232 port.

Consequently, a Frequency Broadcaster module was developed and is now included with Buzz-o-sonic

 

 

Optional Modules**

Lab Kit

Useful for engineering students

A series of pre-tested ceramics, metals and polymers are provided. Some suggested lab experiments are suggested

A special module is used to recall the pre-test data directly into Buzz-o-sonic or into special Excel workbooks

High Temperature

Buzz-o-sonic can be adapted to test samples at high temperature in air, Ar or N2 atmospheres up to ~1700 ⁰C. The furnace, special module, special sample holder, and temperature controls are all provided and customized to the customer's needs. A High Temperature kit, designed to attach our testing fixtures to an existing furnace, is also available.

Cryogenic

Buzz-o-sonic can be adapted to test samples at low, liquid nitrogen temperature ( -196 ⁰C). The cryogenic chamber, special module, special sample holder, and temperature controls are all provided and customized to the customer's needs

 

** These modules require special hardware and therefore are not included with the standard system

 

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BuzzMac International, LLC

+1 (414) 352-5419