k-Wave

1. mabdinur85
   

   Member
   Joined: Jun '13
   Posts: 4

   I would like to create a simulation of an M-Scan composed of several A-Scan's ... I guess time is the axis of motion for the purpose of NDT. As time changes, properties of the medium under test (Aluminium) are changing; ie. temperature resulting in the melting of the medium ... and cooling/ hardening. This has a direct effect on time of flight for a single source sensor/ transducer running in pulse-echo mode.

   Although the material is Aluminium ... I would say that it is more of a heterogeneous medium because the acoustic wave goes through water, copper electrodes, aluminium alloys, and air gaps along the way for each pulse-echo period.

   Also I have done the Initial Value Problem examples to get comfortable with this toolbox and I have scoured the forums for topics that seemed relevant to what I would like to do. One gentleman did ask how to do a time varying medium, and was told I believe by Dr. Treeby that kwave does not support this yet, and alternatively that he can do a moving sensor, which seems interesting to try.

   http://www.k-wave.org/forum/topic/time-varying-media

   Now the point of this thread; I would like to do several simulations that best try to behaviorally model the NDT we are doing in the lab. I would like to know which simulation is a good starting place; I believe just jumping to a 3D simulation doesn't use the toolbox effectively to describe the behavior and I wanted to move up from 1 Dimensional simulations to a final 3D image that can approximate what we obtain in the lab. Any suggestions that can ease a relative new user to the toolbox into simulating what a describe? Lastly as my description says, there are several mediums in the NDT application. Can kwave handle 4-5 different mediums with differing dimensions and shapes? I apologize for asking redundant questions as you probably get asked this every time.

   Posted 11 years ago #

2. bencox
   

   Developer
   Joined: Mar '10
   Posts: 292

   Hi mabdinur85,

   Thanks for your interest in k-Wave. Currently k-Wave models acoustic waves in a fluid, not in a solid (although we're working on that), so it does not model shear waves. I would expect you need a model of elastic wave propagation to simulate waves in aluminium, or is there some reason for your application that means a fluid model is ok?

   Also, as Brad says, we haven't yet incorporated time-varying media although we think it will be possible, at least for media changing slowly on an acoustic timescale. We plan to include it in a later release.

   Ben

   Posted 11 years ago #

3. mabdinur85
   

   Member
   Joined: Jun '13
   Posts: 4

   Thanks for the insight;

   You are right in the assumption that I would require the model to represent the solid aluminium as well as a copper electrode.

   The aluminium is the system under test and does have a liquid phase as it melts. What I am trying to model/ simulate is the welding process between two pieces of aluminium through the use of a spot weld system. We can determine how good the weld is through a variety of methods after the ultrasound images are processed. We have a FEM model of this process but I believe the spectral approach of K-Wave is much more suited to this application. I also think it can help us more in testing different combinations of welding processes that yields the best simulated results that then can hopefully translate to a more effective system.

   For now; I wanted to do the basic set of simulations and build towards a final suite of simulations of the system. I can try to simulate the liquid phase of the weld ... but because it is cooling down and solidifying fairly quickly it makes this a time varying medium.

   I will look around the toolbox and see what I can use to model for now I guess, and I anticipate these future expansions will also expand any simulation I do. If at all possible I can try to extend the shortcomings of the current toolbox by finding some other ways. My current task is to complete all the examples, gain a level of proficiency with the toolbox and go from there.

   Posted 11 years ago #

4. kailiang
   

   Member
   Joined: Dec '15
   Posts: 1

   Hello,
   May I know, in current version of k-Wave, the solid model with shear waves has been considered or not?
   thank you very much for your answering!

   Posted 7 years ago #

5. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi kailiang,

   Yes, you can model solids using the functions pstdElastic2D and pstdElastic3D. See this paper for reference.

   Brad.

   Posted 7 years ago #

RSS feed for this topic

Reply

You must log in to post.