increased mass

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

Hi,

I have the following questions.

1.       I am trying to get the stress strain curves for 2 parts, one with all shells and other with all tetras. I could see the TH plots only for the individual elements, rather I am looking for the complete part. Is it really possible?

2.       I have a couple of spring beam elements for which I have added mass (not input per length). When I check for the mass vs time I could see an increased mass of about 15 times of my assigned value (no ramp but constant mass from 0 msec). Could anyone tell what is causing this?

Any suggestion is highly appreciable

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2017

    Hi Ushay,

    For /TH/PART stress will not be extracted, you can only do this by creating /TH/SHEL.

    Please let me know how did you plot mass vs time plot, that is which keyword you have used in engine file?. Also please upload the plot.

     

  • Ushay
    Ushay Altair Community Member
    edited December 2017

    Hi George,

    Thank you. I have sent the file through Dropbox

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2017

    Hi,

    I tried with a simple model with springs and it displayed the correct mass in TH file.

    Which spring type are you using and also let me know the HyperWorks version you are using.

    Also, please check the mass of that spring component in mass calc (Tools>>mass calc) and send a snapshot of the same.

  • Ushay
    Ushay Altair Community Member
    edited December 2017

    Hi George,

    Could you please send your file, I will check with my HW version. I am using version 13 and when I calculate the mass in hypermesh it shows 0 because stitch type is not supported.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2017

    Hi,

    Please check the mass in HyperCrash (Mass>>Parts Details).

     

    <?xml version="1.0" encoding="UTF-8"?>mass.PNG

     

    Please note that for Type 35 (Stitch) the mass assigned 'Amas' is Mass per unit length. And this could be the reason for the increased mass.

  • Ushay
    Ushay Altair Community Member
    edited December 2017

    Hi George, thanks for this option. Can one plot TH for mass of individual springs rather than the whole part of springs? I do not find the option for the single spring element

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2017

    Hi,

    For /TH/SPRING, mass will not be extracted. Only for /TH/PART you can get mass in output.

  • Ushay
    Ushay Altair Community Member
    edited December 2017

    Thanks George

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