where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

GB Inspection Systems Ltd.
A leading UK manufacturer of Ultrasonic Probes, Accessories, Supplier of NDT Equipment and more.
1591 views
Technical Discussions
Nathan
Nathan
11:40 Jan-27-2009
ULTRASONICS: Shear/Longitudinal Velocity Calculation...

Hi Guys...

What is the calculation to work out the shear wave velocity of a material, if you know the transverse velocity? I know it's approximately half, but is there a formula(e) to work it out?

Hope you can help?

Nathan

 
 Reply 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 869

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
869
12:56 Jan-27-2009
Re: ULTRASONICS: Shear/Longitudinal Velocity Calculation...
In Reply to Nathan at 11:40 Jan-27-2009 (Opening).

Nathan,

The link below will bring you the Table of Materials Properties for UT inspection. Another source is the Metal's Handbook from the American Society of Materials.

http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Reference%20Information/UT/ut_matlprop_metals.htm

Cheerio's

 
 Reply 
 
Thomas Vogt
R & D, - -
Guided Ultrasonics Ltd, United Kingdom, Joined Apr 2007, 22

Thomas Vogt

R & D, - -
Guided Ultrasonics Ltd,
United Kingdom,
Joined Apr 2007
22
14:38 Jan-27-2009
Re: ULTRASONICS: Shear/Longitudinal Velocity Calculation...
In Reply to Nathan at 11:40 Jan-27-2009 (Opening).

Nathan,

I think you mean longitudinal instead of transverse, but nevertheless, the first thing to realize is that the shear and longitudinal velocities of a material are entirely independent. Together with the density they define the elastic properties of a material, so you cannot work one out purely from the other. You have to look it up in the table as Michel suggested.

However, you can derive a lower (theoretical) limit for the longitudinal velocity: The longitudinal velocity must be greater than the shear velocity times the square root of 2 [in a formula: v_l > v_s*sqrt(2)].

Hope this helps,
Tom

 
 Reply 
 
Richard Freemantle
NDT Inspector, Consultant, R&D
Wavelength NDT Limited, United Kingdom, Joined Nov 1998, 16

Richard Freemantle

NDT Inspector, Consultant, R&D
Wavelength NDT Limited,
United Kingdom,
Joined Nov 1998
16
15:09 Jan-27-2009
Re: ULTRASONICS: Shear/Longitudinal Velocity Calculation...
In Reply to Thomas Vogt at 14:38 Jan-27-2009 .

Hi,

Just to add to Tom's comments, as far as I remember the longitudinal velocity can be directly related to the shear velocity provided you know the Poisson's ratio for the material. Do you have this value for the materials you are interested in ? If so I can try and dig out the equation for you !

Hope this helps,

Regards,

Richard

 
 Reply 
 
James Barshinger
Engineering
General Electric Global Research Center, USA, Joined Aug 2000, 8

James Barshinger

Engineering
General Electric Global Research Center,
USA,
Joined Aug 2000
8
17:58 Jan-27-2009
Re: ULTRASONICS: Shear/Longitudinal Velocity Calculation...
In Reply to Richard Freemantle at 15:09 Jan-27-2009 .

The equation relating shear velocity to longitudinal velocity is CT=CL*sqrt((1-2u)/(2(1-u))) where u=Poisson's ratio.

-Jim

 
 Reply 
 

Product Spotlight

IntraPhase Athena Phased Array System

The Athena Phased Array system, manufactured by WesDyne NDE Products & Technology, consists of a pha
...
sed array acquisition system and PC running IntraSpect software. A PC is used to perform acquisition, analysis and storage of the data. System hardware is capable of operating up to four data sets with any combination of phased array or conventional UT probes. NOW AVAILABLE IN 64-64 CONFIGURATION.
>

Compact NDT inspection-heads for measurements with active thermography

The compact inspection head is suitable for thermographic ndt tasks. The uncooled infrared camera
...
is specially developed for NDI-tasks and offers a thermal sensitivity until now known only from thermal imagers with cooled detector. All required components and functions are integrated into the inspection-head. You will only need an ethernet cable to connect the sensor with the evaluation system.
>

Customized Probes and Transducers

With a strong development department and our own piezocomposite production, we accompany you from th
...
e first product idea to serial production. Our scientists are continuously researching new methods in the field of ultrasonic measurement technology. The progress achieved enables us to offer you optimal solutions.
>

NovaScope 6000

The all-digital Novascope 6000 is a portable, ultra-high precision thickness gauge for high-speed
...
thickness measurement. Novascope 6000 has unmatched capabilities and unique features including: •Superior Resolution with high contrast, high-speed color RF display •High pulser voltage •Real-time video output •Increased internal/external data storage •Programmable SetUp features •Battery & AC Powered
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window