Is there a method to linearly distribute a moment on edges?

Oskar Neumann
Oskar Neumann Altair Community Member
edited October 2020 in Community Q&A

Hello, I want to apply a load to the edge of a symmetric model, starting with a moment of 0 on the symmetry edge node and increasing linearly to the outermost node of the (load-) edge (see picture).

 

How can a moment be distributed in this way? 

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

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Answers

  • Adriano A. Koga
    Adriano A. Koga
    Altair Employee
    edited August 2020

    you can accomplish that using the 'equation' option in 'moments' panel.

    You define a reference system (or global, depending on your coordinates), and then create the moment distribution using this system and an equation like shown below. (x is your x-coordinate along the local system).

     

    You just need to write the equation correcly so that the last value is 1.

    Something like: (1/your_length)*x

    <?xml version="1.0" encoding="UTF-8"?>image.thumb.png.3f66c151a13611a4c2d4f6617c381afc.png

  • Oskar Neumann
    Oskar Neumann Altair Community Member
    edited August 2020

    Thank you Adriano, which .tcl code is corresponding to this?

     

    If been working with *loadcreateonentity so far, but the docu does not provide me with more inside.

     

    *loadcreateonentity
    Creates a load (forces, temperature, moment, velocity, acceleration, or constraints) on nodes, fixed
    points (surface vertices or weld points), surface edges, and surfaces.
    Syntax
    *loadcreateonentity geomtype markmask config type component[1-6]
    Type
    HyperMesh Tcl Modify Command
    Proprietary Information of Altair Engineering
    Altair HyperMesh 2020 Reference Guide
    Scripts p.1274
    Description
    Creates a load (forces, temperature, moment, velocity, acceleration, or constraints) on nodes, fixed
    points (surface vertices or weld points), surface edges, and surfaces.
    Inputs
    geomtype
    Type of entity the load is applied on (e.g. SURFS).
    markmask
    The ID of a mark containing the entities that will bear the load.
    config
    The configuration of the load:
    1 - Force
    2 - Moment
    3 - Constraint
    5 - Temperature
    6 - Flux
    8 - Velocity
    9 - Acceleration
    type
    The type assigned to the load (as defined on the 'load types' panel).
    component[1-6])
    Components of the load being applied.
    When applying a force, the active components are 1, 2, and 3, which represent a force x, y, and
    z-axis, respectively.
    When applying a moment, the active components are also 1, 2, and 3, and represent the moment
    about the x, y, and z-axis, respectively.
    For constraints, all of the components are active unless they are set equal to -999999.0. All the
    other components of the constraints are active in the respective directions.

  • Adriano A. Koga
    Adriano A. Koga
    Altair Employee
    edited August 2020

    you're doing something that many people often skip, that is to go thorugh the documentation, which is great! :)/emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

     

    but in your particular case, concerning scripts, sometimes is easier to just perform the operation manually in HM first and take a look at the 'command.tcl' file created in documents folder.

     

    look at the commands below:

    *createmark nodes 1 a bunch of nodes......

    *loadcreateonentity_function nodes 1 2 1 0 0 1 0 0 1 0 0 0 '3*x'

     

    some of these arguments are the global system that i've selected and some of them are the direction (z 0 0 1)

    Now looking at the help you whould be able to find more about this command.

  • Oskar Neumann
    Oskar Neumann Altair Community Member
    edited August 2020

    Thank you very much, Adriano. I didn't know that there are commands that are not documented in the scripting reference manual.