Loadcell barriers doubts

Help in understanding TS 13499
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Miguel A Gallego
Posts: 3
Joined: Mon Apr 20, 2020 8:24 am
Company: Applus IDIADA Group

Loadcell barriers doubts

Post by Miguel A Gallego » Fri Apr 24, 2020 9:29 am

Dear all,

I have several doubts regarding Load Cell barriers that I would like to clarify.In the object information file:

1.When the reference system id, should be B/MST or B/MT0?? I think that BST/MST should be used for Static measures (for instance a scan of the DEFO element) and BT0/MT0 for the measures that loadcells are acquiring during the test. Am I right?? Or other criteria should be used?? REDA Pag 35 section 4.1.2.2 Is showing BST but I think that MST wouldn´t be right for loadcells acquisition… Would it?

2. If what I exposed before were right, which reference system id (could exist 2 different refsys id for the same object) would be used in the test object.mmi?

3. Fields Origin X, Y & Z in [m] are mandatory in object.mmi (only for loadcell matrix) but the origin is defined in the reference_system.mmi as string. Why an origin different than the one defined in reference system.mmi could be possible and needed to be recorded? And the origin distance in meters regarding what? Could be these fields “NOVALUE” or “0”?

I would like to finish by asking if REDC:2019E pag 91 first image (Full Width loadcell matrix) second ISOcode example ?0LOMA001975FO? could be wrong. I think the proper code for the position showed is ?0LOMA001972FO? Is that right?

Thank’s in advance and best regards

Miguel Ángel

derpmann
Posts: 441
Joined: Tue Apr 24, 2007 5:32 am
Location: Volkswagen AG, Wolfsburg - Germany

Re: Loadcell barriers doubts

Post by derpmann » Wed May 20, 2020 10:10 am

Dear Miguel,
the testobject code B is used for fixed barriers and M for movable barriers.
For static measurements before or after the test ST is used,
for the situation at T0 T0 has to be used.

For scans before or after the test this results in the reference system id BST for fixed barriers and MST for movable barriers.
For the reference system id in the barrier information file the static situation has to be used.
You are right, this is not explicitly written down.
In real situations I assume the loadcell matrix at T0 will be equal to the position before the test.

Reply to question 1:
Yes, you are right, but in the eaxmple 4.1.2.2 a loadcell mounted on a fixed barrier should be shown.
Therefore the reference system id BST.

Reply to question 2:
For a testobject 2 or 3 reference coordinate systems are possible, but only the static one should be used in the mmi file.

Reply to question 3:
In the reference system mmi file only informative descriptions are recorded.
This is important, when the origin and directions are not given by regulations or other specification.
In the case of barrier systems with loadcells in 1.3.3.1 the origin is given by:
top left corner of the loadcell matrix
If you use this definition the Origin X and Origin Y values have to be 0.

Reply to question 4:
Yes you are right. The code has to be ?0LOMA001972FO? in the second row of the example :o

Best regards
Peter

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