INIV_TRA_1

Nancy Jewel Mcdonie
Nancy Jewel Mcdonie Altair Community Member
edited May 17 in Community Q&A

Hi all, 

Does anyone know how to use this ENGINE KEYWORD  (INIV/TRA/1) in Radioss?

and, another question, I want to do a crash test, simulated impacting at 50km/h so what engine keyword i need to use in this case?

Thanks. 

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Best Answer

  • Edouard Ferry_20577
    Edouard Ferry_20577
    Altair Employee
    edited April 23 Answer ✓

    Hi Nancy,

    The /INIV/TRA/1 keyword is used to apply an initial velocity to a range of nodes. For example, if you want to apply a velocity of 50 km/h along Y-axis to the range of node IDs from 1000 to 2500 and to the range of node IDs from 4200 to 65120, you can write (if your unit system is in km and h, otherwise you need to convert your velocity value):

    /INIV/TRA/Y/1
    50
    1000 2500 4200 65120

    If you want to apply a velocity to single node IDs (not a range), you can use /INIV/TRA/Y.

    If you want to apply a velocity to a group of nodes (already existing in your model file xxx_0000.rad), you can use /INIV/TRA/Y/2.


    These keywords are engine keywords, which means you must write them in an engine file (xxx_0001.rad , xxx_0002.rad ...). These keywords are used to apply a velocity to nodes during a simulation, at a given time. You will probably need to stop your simulation at the time you want to apply the velocity (final time of xxx_0001.rad file for example) and write the keywords in your following engine file (xxx_0002.rad for example).

    If you want to apply a velocity at the beginning of your simulation (t=0), I would recommend using the block format keyword /INIVEL directly in your model file (xxx_0000.rad), even if the engine keywords will also do the job.

    So to answer your second question, if you want to perform a crash test at 50km/h, be sure to convert this value into the unit system of your model and depending on your needs, you can use:

    - /INIVEL in the 0.rad file if you want to apply the velocity at t=0
    - /INIV/TRA in the engine file, usually not at t=0, if you want to specify all the IDs of the nodes you want to apply the velocity on
    - /INIV/TRA/1 in the engine file, usually not at t=0, if you want to specify a range of nodes 
    - /INIV/TRA/2 in the engine file, usually not at t=0, if you want to specify a group of nodes

    I hope this is clear and answers your questions.
    Edouard

Answers

  • Edouard Ferry_20577
    Edouard Ferry_20577
    Altair Employee
    edited April 23 Answer ✓

    Hi Nancy,

    The /INIV/TRA/1 keyword is used to apply an initial velocity to a range of nodes. For example, if you want to apply a velocity of 50 km/h along Y-axis to the range of node IDs from 1000 to 2500 and to the range of node IDs from 4200 to 65120, you can write (if your unit system is in km and h, otherwise you need to convert your velocity value):

    /INIV/TRA/Y/1
    50
    1000 2500 4200 65120

    If you want to apply a velocity to single node IDs (not a range), you can use /INIV/TRA/Y.

    If you want to apply a velocity to a group of nodes (already existing in your model file xxx_0000.rad), you can use /INIV/TRA/Y/2.


    These keywords are engine keywords, which means you must write them in an engine file (xxx_0001.rad , xxx_0002.rad ...). These keywords are used to apply a velocity to nodes during a simulation, at a given time. You will probably need to stop your simulation at the time you want to apply the velocity (final time of xxx_0001.rad file for example) and write the keywords in your following engine file (xxx_0002.rad for example).

    If you want to apply a velocity at the beginning of your simulation (t=0), I would recommend using the block format keyword /INIVEL directly in your model file (xxx_0000.rad), even if the engine keywords will also do the job.

    So to answer your second question, if you want to perform a crash test at 50km/h, be sure to convert this value into the unit system of your model and depending on your needs, you can use:

    - /INIVEL in the 0.rad file if you want to apply the velocity at t=0
    - /INIV/TRA in the engine file, usually not at t=0, if you want to specify all the IDs of the nodes you want to apply the velocity on
    - /INIV/TRA/1 in the engine file, usually not at t=0, if you want to specify a range of nodes 
    - /INIV/TRA/2 in the engine file, usually not at t=0, if you want to specify a group of nodes

    I hope this is clear and answers your questions.
    Edouard

  • Nancy Jewel Mcdonie
    Nancy Jewel Mcdonie Altair Community Member
    edited April 23
    Edouard Ferry_20577 said:

    Hi Nancy,

    The /INIV/TRA/1 keyword is used to apply an initial velocity to a range of nodes. For example, if you want to apply a velocity of 50 km/h along Y-axis to the range of node IDs from 1000 to 2500 and to the range of node IDs from 4200 to 65120, you can write (if your unit system is in km and h, otherwise you need to convert your velocity value):

    /INIV/TRA/Y/1
    50
    1000 2500 4200 65120

    If you want to apply a velocity to single node IDs (not a range), you can use /INIV/TRA/Y.

    If you want to apply a velocity to a group of nodes (already existing in your model file xxx_0000.rad), you can use /INIV/TRA/Y/2.


    These keywords are engine keywords, which means you must write them in an engine file (xxx_0001.rad , xxx_0002.rad ...). These keywords are used to apply a velocity to nodes during a simulation, at a given time. You will probably need to stop your simulation at the time you want to apply the velocity (final time of xxx_0001.rad file for example) and write the keywords in your following engine file (xxx_0002.rad for example).

    If you want to apply a velocity at the beginning of your simulation (t=0), I would recommend using the block format keyword /INIVEL directly in your model file (xxx_0000.rad), even if the engine keywords will also do the job.

    So to answer your second question, if you want to perform a crash test at 50km/h, be sure to convert this value into the unit system of your model and depending on your needs, you can use:

    - /INIVEL in the 0.rad file if you want to apply the velocity at t=0
    - /INIV/TRA in the engine file, usually not at t=0, if you want to specify all the IDs of the nodes you want to apply the velocity on
    - /INIV/TRA/1 in the engine file, usually not at t=0, if you want to specify a range of nodes 
    - /INIV/TRA/2 in the engine file, usually not at t=0, if you want to specify a group of nodes

    I hope this is clear and answers your questions.
    Edouard

    Thank you so much, Edouard!

  • Nancy Jewel Mcdonie
    Nancy Jewel Mcdonie Altair Community Member
    edited May 17
    Edouard Ferry_20577 said:

    Hi Nancy,

    The /INIV/TRA/1 keyword is used to apply an initial velocity to a range of nodes. For example, if you want to apply a velocity of 50 km/h along Y-axis to the range of node IDs from 1000 to 2500 and to the range of node IDs from 4200 to 65120, you can write (if your unit system is in km and h, otherwise you need to convert your velocity value):

    /INIV/TRA/Y/1
    50
    1000 2500 4200 65120

    If you want to apply a velocity to single node IDs (not a range), you can use /INIV/TRA/Y.

    If you want to apply a velocity to a group of nodes (already existing in your model file xxx_0000.rad), you can use /INIV/TRA/Y/2.


    These keywords are engine keywords, which means you must write them in an engine file (xxx_0001.rad , xxx_0002.rad ...). These keywords are used to apply a velocity to nodes during a simulation, at a given time. You will probably need to stop your simulation at the time you want to apply the velocity (final time of xxx_0001.rad file for example) and write the keywords in your following engine file (xxx_0002.rad for example).

    If you want to apply a velocity at the beginning of your simulation (t=0), I would recommend using the block format keyword /INIVEL directly in your model file (xxx_0000.rad), even if the engine keywords will also do the job.

    So to answer your second question, if you want to perform a crash test at 50km/h, be sure to convert this value into the unit system of your model and depending on your needs, you can use:

    - /INIVEL in the 0.rad file if you want to apply the velocity at t=0
    - /INIV/TRA in the engine file, usually not at t=0, if you want to specify all the IDs of the nodes you want to apply the velocity on
    - /INIV/TRA/1 in the engine file, usually not at t=0, if you want to specify a range of nodes 
    - /INIV/TRA/2 in the engine file, usually not at t=0, if you want to specify a group of nodes

    I hope this is clear and answers your questions.
    Edouard

    Hi Edouard, with /INIV/TRA/1, how can I know when the velocity is applied for a range of nodes as you said? (usually not at t = 0)

  • Edouard Ferry_20577
    Edouard Ferry_20577
    Altair Employee
    edited May 17
    Nancy Jewel Mcdonie said:

    Hi Edouard, with /INIV/TRA/1, how can I know when the velocity is applied for a range of nodes as you said? (usually not at t = 0)

    Hi Nancy,

    As /INIV/TRA/1 is an engine keyword (any .rad file except the 0.rad file), it will apply as soon as the engine file is read. If you want to apply an initial velocity at a given time, I would recommend:

    - creating your model WITHOUT velocity (0.rad file)
    - running the simulation wiht a 1.rad file WITHOUT initial velocity, until the time at which you want to initiate the velocity (for example 1ms). The simulation will run until 1ms WITHOUT initial velocity.
    - continuing the simulation with a 2.rad file WITH the card /INIV/TRA/1. This initial velocity will apply as soon as the 2.rad is read, which means at 1ms. And you can set the final time of your simulation in the 2.rad file.

    Let me know if it works as expected on your side.

    Edouard

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