FORCE VS DISPLACEMENT GRAPH AND TIME VS DISPLACEMENT GRAPH

NoorAlam_08
NoorAlam_08 Altair Community Member
edited October 2020 in Community Q&A

Hello Everyone,

 

i am doing Non linear quasi static  analysis using Radioss solver, 

Loading condition is Force ramp vs Time, but i am unable to find force vs Displacement graph and Time vs Displacement graph in Hypergraph by .T01 file.

Can anyone please let me know which input control is used to find load vs displacement and time vs displacement graph.

Regards

Noor Alam. 

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited September 2019

    Hi,

     

    only global variables like energy balance, timestep, mass, etc. are output by default to the time history file. Specific quantities of interest have to be requested by output blocks.

     

    Refer to step 8: Create Time History Output the attached tutorial on how to define force output request of a rigid body.

    Alternatively, the force output request can also be defined in a cross-section. Referer to step 17: Create a Cross Section and then set up a TH/SECTIO output request. 

    Plot the appropriate X and Y components in Hypergraph.

    <?xml version="1.0" encoding="UTF-8"?>force-displacement.jpg

    The cross-plot function may also be useful:

    https://insider.altairhyperworks.com/wp-content/uploads/2018/02/T-T-1292-HyperGraph-Cross-Plot.pdf

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  • NoorAlam_08
    NoorAlam_08 Altair Community Member
    edited September 2019

    Thanks 

    Hi,

     

    only global variables like energy balance, timestep, mass, etc. are output by default to the time history file. Specific quantities of interest have to be requested by output blocks.

     

    Refer to step 8: Create Time History Output the attached tutorial on how to define force output request of a rigid body.

    Alternatively, the force output request can also be defined in a cross-section. Referer to step 17: Create a Cross Section and then set up a TH/SECTIO output request. 

    Plot the appropriate X and Y components in Hypergraph.

    <?xml version="1.0" encoding="UTF-8"?>force-displacement.jpg

    The cross-plot function may also be useful:

    https://insider.altairhyperworks.com/wp-content/uploads/2018/02/T-T-1292-HyperGraph-Cross-Plot.pdf

     

     

    Thanks, hyperman,

     

     

    i have one another issue , some time error % is going to very low which is highlighted in below, 

    i am not aware why this is going very low, i also realised some time due to this my remaining time is increases,

     

    Please let me know if error % is negative then what its mean, Solution is going correct or wrong,

    if due to this solution is going wrong then what error should be there in model.

     

     

     

    image.png.b1f71385b4ba2a8cec6b74ccf6437b11.png

     

     

    regards,

     

    NOOR ALAM

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  • NoorAlam_08
    NoorAlam_08 Altair Community Member
    edited September 2019

    Thanks 

     

     

    Thanks, hyperman,

     

     

    i have one another issue , some time error % is going to very low which is highlighted in below, 

    i am not aware why this is going very low, i also realised some time due to this my remaining time is increases,

     

    Please let me know if error % is negative then what its mean, Solution is going correct or wrong,

    if due to this solution is going wrong then what error should be there in model.

     

     

     

    <?xml version="1.0" encoding="UTF-8"?>image.png.b1f71385b4ba2a8cec6b74ccf6437b11.png

     

     

    regards,

     

    NOOR ALAM

     

     

     

    Hello Hyperman,

     

    i am doing rd 3500 tutorial during ran the tutorial, i am geting this eroor,

    please let me know why this error is coming, i am sending  time history setup as well as error message screen shoot.

     

    image.png.1cf8e536955e68b74d38c40283df5295.pngimage.png.be60330402e8b918941c539ced67086c.pngimage.png.5ae2e668346b90fc84a922e5f06d1cfc.png

    regards

    Noor Alam

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited September 2019

    Hi,

     

    negative energy error represents energy dissipated from the system and this can be from many sources like plastic deformation, hourglass energy,  contact with friction, damping,... Review the energy balance to identify the source of this error. Since the energy error is high in combination with timestep drop (remaining time increasing) my guess is hourglass issue. Use Isolid/Ishell=12 or 24 and try running the simulation. 

    <?xml version="1.0" encoding="UTF-8"?>Energy_Error_Explained__RadiossHelpFiles.jpg

    Check the out file for warnings and errors. In this case the error 1109 is because no variable is defined for output request. The default output requests are defined by entering DEF in the Data: Var table. 

  • NoorAlam_08
    NoorAlam_08 Altair Community Member
    edited September 2019

    Hi,

     

    negative energy error represents energy dissipated from the system and this can be from many sources like plastic deformation, hourglass energy,  contact with friction, damping,... Review the energy balance to identify the source of this error. Since the energy error is high in combination with timestep drop (remaining time increasing) my guess is hourglass issue. Use Isolid/Ishell=12 or 24 and try running the simulation. 

    <?xml version="1.0" encoding="UTF-8"?>Energy_Error_Explained__RadiossHelpFiles.jpg

    Check the out file for warnings and errors. In this case the error 1109 is because no variable is defined for output request. The default output requests are defined by entering DEF in the Data: Var table. 

    hello 

     

    Please let me know where output variable will be created ,  like which control card will be use for output variable create.

    Regards 

    Noor Alam

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited September 2019

     

  • NoorAlam_08
    NoorAlam_08 Altair Community Member
    edited September 2019

    Hi,

     

    negative energy error represents energy dissipated from the system and this can be from many sources like plastic deformation, hourglass energy,  contact with friction, damping,... Review the energy balance to identify the source of this error. Since the energy error is high in combination with timestep drop (remaining time increasing) my guess is hourglass issue. Use Isolid/Ishell=12 or 24 and try running the simulation. 

    <?xml version="1.0" encoding="UTF-8"?>Energy_Error_Explained__RadiossHelpFiles.jpg

    Check the out file for warnings and errors. In this case the error 1109 is because no variable is defined for output request. The default output requests are defined by entering DEF in the Data: Var table. 

     

    Hello Hyperman,

     

    thanks for your reply,

     

    as per your as per your comment i have check all all the model,as i understand there is no any issue,

    but still i am face same problem, like % error is negative. for your reference i am attaching .out file,

     

    please let me know what is the issue of this error.

    image.png.e80db8681d6578edfd0bbedab9338c5f.png

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