Orient Bar2 or Bar3 Elements

Use the Edit Beam: Orient tool to define bar2 or bar3 orientation.

Each solver profile manages beam orientation in a different way and provides more or less flexibility to define orientation, such as vector or third node. However, despite such variability in the way solver realizes orientation, the context options remain almost unchanged and hide the complexity. However, if an option is irrelevant for a given solver, it will be hidden.

Plane1 is the plane defined by an element's X-axis and orientation method. Depending on the solver, this will be either the XY plane or the XZ plane.
Figure 1. OptiStruct Solver Bar2 Orientation


Although HyperMesh has a Global system (system ID=0), some solvers (for example, OptiStruct/Nastran) use global to denote the node's output system and use Basic to refer to laboratory global system. Basic and Displacement are used for the laboratory reference system or the node output system in which displacement components are written.

  1. From the 1D ribbon, click the Edit Beam > Orient tool.
    Figure 2.


  2. Select elements to orient.
  3. Optional: On the guide bar, click to define orientation options.
  4. Orient using a reference node, clear the By Vector check box.
    1. Select a node to use as 3rd node.
      The same node reference is used by all target elements to orient.
  5. Orient using a reference element, clear By Vector check box.
    1. Select a reference element.
      The orientation of a reference element is propagated to target elements to orient.

      Implementation varies depending on the solver profile.

  6. Orient using a vector as a method.
    1. Select the By Vector check box.
    2. Use the options in the microdialog to orient.
    OptionDescription
    Orient Bar2/Bar3 as Plate Stiffener Click to align the bar2/bar3 vertical axis along the positive normal of an adjacent shell.

    Normals of adjacent shells are averaged since they do not have an angle greater than the threshold value (break angle) defined in the options. For sharp angles, the shell with the lowest ID is used as a reference. In the case of T-junctions, you can select a reference shell by hiding undesired shells and by setting the "Normal from shells" option to Displayed.
    Rotate Elements Along the X-Axis - dynamically rotate Plane 1 using a manipulator. The same rotation angle will be applied to element selection from their original orientation.

    Click in the microdialog to expose the incremental option.
    Vector Tool and Systems Provide an arbitrary orientation vector in space using the Vector tool.
    1. Click .
    2. Orient the vector then press Esc to return to the current tool.

    In the manipulator microdialog, you can select a local system to resolve vector coordinates. Click to pick a system.

    Use the vector manipulator or enter x, y, z components (resolved in local system).
    Orient in Displacement System Define orientation vector components in Node1’s output system.
    1. Click in the Orient microdialog to expand the microdialog.
    2. Enter X, Y, Z components of orientation vector in displacement system.
    Restriction: This option is not available for all solver profiles.
    Replace Orient by Vector In case the beam uses a node for orientation, use this option to replace the node with an equivalent vector. The vector goes from the beam node 1 to the orientation node.

    Click in the Orient microdialog then select Replace orient by vector.

    If you select a beam that has no node, the option does nothing.

    Restriction: This option is only available in solver profiles which natively support orientation by vector.
Tip: Use the legend in the top-left of the modeling window to plot the axes of the elemental systems that result from the current orientation.
Restriction: The following are for OptiStruct and Nastran only:
  • The orientation direction defines the XY planes. Hence, whenever orientation is set along shell normal, theY-axis matches with shell positive normal as a result.
  • All orientation methods, but picking reference node result on X,Y,Z orientation vector, are saved at element level.
  • Using the Orientation by Vector tool (with or without system) will assign the OFFT key for orient as B. This means components are expressed in Basic system, see Figure 3.
  • Using Orientation in displacement system will set OFFT for orientation as G, see Figure 3.
  • Replace Orient by vector is available.
Restriction: The following are for ANSYS only:
  • The orientation direction defines the XZ planes. Hence, whenever orientation is set along shell normal, the Z-axis matches with shell positive normal as a result.
  • All orientation methods result in the creation or update of a third node on each bar2/bar3. Hence, there is no concern of Basic/Displacement system.
  • Replace Orient by vector is not available as it is meaningless.
Figure 3.