How does Diadem calculate Chest Wall Velocity in Crash Toolkit?

[berkayaga]

My calculations from a other program for CWV is differrent from Diadem. There is no information in diadem only a link for the standart

and I would like to know the constants and the equation for calculating Chest Wall Velocity.

For further information such as mathematical background, input values, directives and rules, refer to the web site RTO-TR-HFM-090 Test Methodology for Protection of Vehicle Occupants against Anti-Vehicular Landmine ... in paragraph 3.6.2.3 of the third chapter and in paragraph 1.2.2.1 of Appendix I.

Thank you,

[berkayaga]

Hi everyone,

In the Crash test tool kit, there is a tool named CVW(Chest Wall Velocity). This tool calculates injury criteria for blast(explosion) events. If you calculate this parameter correct you can predict that, people from this blast event survived or not. 

Right now I am sure that Diadem calculates this parameter wrong. I wrote a vi with labview and also with an another simulation program and compared the results. Only different result is calculated by diadem. And the difference is huge. You can check the graphs in the attachment.  

I think the righteous way for this type of calculations is the hard way. 

[Renée]

berkayaga,

Which version of Diadem are you using?

Can you explain what you are showing in your two different attachments?

[Brad_Turpin]

Hi berkayaga,

R&D is willing to look into this for you, but they request that you send the resulting data sets from both your external application and the results that DIAdem delivers.  If you're uncomfortable posting data to the forum, feel free to email it to me directly at brad.turpin@ni.com

Brad Turpin

DIAdem Product Support Engineer

National Instruments

[berkayaga]

Hi Renee,

Version is 2011. There are two data sets for each file. In each file I am comparing the CVW results of calculations. You can see the difference between diadem and the other two software. Graphs shapes and also the amplitudes are different. Graphs should be the same. Cause data is same for each file.

Regards,

[Frizzit]

I'm curious if you have validated the DRI x, y, and z calculations as well.  Let me know how this unfolds, I have a coulple of corrections to make if the CWV is calculating incorrectly. 

[berkayaga]

Yes, I have validated DRIz calculation. I have used labview and matlab to correct DRIz calculation. Also for the CWV I use the same way.

Could you send me the corrections you made? I would like to check my calculations with your data.

[Frizzit]

I did not make corrections.  I was saying if there are corrections to be made I will have some data from previous testing to fix.  Have you reviewed HFM090 annex H.  This goes through a couple Overpressure injury indicators.

[berkayaga]

Yes, I know that doc. AEP55 uses the Axelsson model for the injury prediction. Diadem and the vi that I wrote also uses the Axelsson model.

Send me your data, I will provide you the results of DRI and CWVp.

[Frizzit]

It is not data I can share.  Thank you for the offer.  I do not have MATLab or Labview on my computer either to run a double check.  I could talk with the motion control guy here and see if we can make a quick VI to run the data.  If we can get a couple double checks on the process we can confirm weather or not the software is calculating properly.