IP Impact

Use the IP Impact tools to automatically calculate the instrument panel (IP) testing area according to the regulations FMVSS201 and ECE-R21, position the headform impactor, and export ready-to-run solver decks for all the selected impact locations.

The tool supports Left- and Right-hand drive vehicles and is accessible from the Safety ribbon. A pull-down menu provides a choice between the Marking and Positioning workflows.
Figure 1.


IP Marking

  1. Click on the guide bar to define marking options.
    Method
    Marking method:
    Automatic
    The marking is performed as per the selected regulation
    Test Lab
    Direct import of impact locations from test lab data using a CSV file.
    Manual
    Impact locations defined by selecting nodes on the IP.
    Vehicle Front Axis
    Orientation of the vehicle -X or +X.
    Regulation
    Regulation to be followed for the marking: FMVSS201 or ECE-R21.
    H-Point Offset
    Method to define the seat reference point offset:
    None
    No offset point.
    XZ Offset
    As per the regulation, with translation in X and Z directions.
    Travel Vector
    User-defined translation vector.
    Target Points
    Method to define the target points locations:
    By Contact Point
    The point of contact between IP and pendulum as defined in the regulation.
    By Distance
    The impact locations are created on the curve with a user-defined distance between them. The curve is created as per the regulation. The distance between 2 locations is defined by the parameter “Distance".
    On Y-Section Line
    The impact locations are created on the cross-section line of the IP parts with Y-planes defined by the Distance value. Impact points are created on upper and lower limit lines, and in between as per the Number of Points value.
    Intermediate Curves
    Creates additional curves and impact locations between the upper and lower impact zone limits.
    LHS Area Limit
    Left limit of the impact zone according to the regulation.
    RHS Area Limit
    Right limit of the impact zone according to the regulation.
    Arm Length
    Arm length used for calculating pendulum positioning parameters.
    The Arm Length is considered to be the distance from the pivot to the top of the headform.
    Min Length
    Minimum pendulum arm length for the lower limit of the impact zone according to the regulation.
    Max Length
    Maximum pendulum arm length for the lower limit of the impact zone according to the regulation.
    Headform Dia
    Headform diameter according to the regulation.
    Rotation Step
    Angle of rotation between two pendulum positions to create the lines on the IP.
  2. For the Automatic and Manual methods, select the entities required.
    Click and to cycle through the entity types for the marking process.
  3. Click Mark to start the marking process.
    The button becomes active when at least the Instrument Panel entities are selected.
  4. Click at the end of the guide bar to move to the IP Positioning workflow.
Tip: Click after each selector to reset your selection. Click at the end of the guide bar to delete all marking entities previously created.

Automatic Marking

Automatic marking performs the calculation of the impact area as per the FMVSS201 and ECE-R21 regulations. At least one of the seat reference point coordinates and the Instrumental Panel components must be defined to enable the marking process.
Figure 2. Instrumental Panel components


Steering wheel and Windshield can be selected for the calculation of the limits of the impact area as defined in the regulation.

At the end of the marking workflow, the following entities are generated:

Geometrical lines
Defining the upper and lower limits of the impact area.
Figure 3. Geometrical lines


Sphere surfaces
Defining the construction of the upper limit for the FMVSS201 regulation.
Figure 4. Upper limit line construction spheres


Planes
Defining the right and left limits of the impact area as per the regulations.
Figure 5. Planes for right and left limits


Impactor geometries
Defining the position of the impactor used for the impact area lines generation.
Figure 6. Impactor position for lines construction


Design Points entities
Defining entities at the calculated impact locations.
Figure 7. Target points entities at impact locations


Impactor geometries
Defining the pre-calculated impactor position with the given Arm Length.
Figure 8. Impactor position for given Arm Length
The graphical display of each of this entity can be activated or deactivated from the legend at the top left corner of the modeling window.
Figure 9.


Manual Marking

Manual marking allows you to create a Design Point entity at a selected location on the IP. A minimum of Design Point entity metadata can be specified in the options menu.

Figure 10.


Select the impact location from the guide bar. Click Mark to automatically generate the Design Point entities.

Figure 11.


Test Lab Marking

Test Lab marking allows you to directly read a CVS file containing the information for the impact locations that a test laboratory can provide.

Select the CSV file from the options menu options then click Mark to automatically create the Design Point entities at the defined locations.

Figure 12.


Here is an example of a CSV file:

Figure 13.


IP Positioning

After the creation of Design Points from the Marking process, the Positioning workflow is used to:

  • Calculate the position of the impactor for all the selected Design Points.
  • Visualize the position of the impactor.
  • Export ready-to-run solver decks for all the selected Design Points
  1. Click on the guide bar to define positioning and export deck options.
    Vehicle Front Axis
    Orientation of the vehicle -X or +X.
    Positioning Method
    Choose between the following positioning methods:
    • Automatic
    • Tangent to Trajectory
    • Normal to Target
    • Pivot/Angles
    • Target/Angles
    • Constant angle in Y-Plane: Selecting this method, for each selected impact point, the top most forward impact location in the same Y-plane is found. On this point, the Tangent to Trajectory positioning method is applied to calculate the V-Angle and apply the Move back Angle value. This V-Angle and the Move back Angle value are then copied to all of the selected points in the same Y-plane section and the positioning method is defined as Pivot/Angles. The Pivot coordinates are automatically calculated for all of the points.
    Transformation Type
    Choose between the following solver transformation definitions for the impactor position:
    LS-DYNA
    • *NODE_TRANSFORM
    • *INCLUDE_TRANSFORM
    Radioss
    • /GRNOD
    • //SUBMODEL
    Main File
    File path to the main input deck to be used for the generation of the decks.
    Headform File
    File path to the headform input deck to be used as include file in the main input deck.
    Output Directory
    Directory where all solver decks for the selected impact locations to be simulated are created.
    Design Point name for the directories and include file name
    This option takes the name of the Design Point entity for the creation of sub-folders and solver deck names.
    Create a folder for each design point in Export Directory
    When ON, this option creates a sub-folder per selected Target Point in the Output Directory location. When OFF, all main decks and includes are written in the Output Directory location.
  2. Select the entities required.
    Click and to cycle through the entity types for the positioning process.
  3. Click Position to display the impactor position for all selected Design Points.
  4. Click Export to export solver decks for all selected Design Points.
    You do not need to first calculate the Position of the impactor before exporting the decks. If not performed before, the position of the impactor is calculated during the export process.
  5. Click at the end of the guide bar to move to the IP Marking workflow.
Tip: Click after each selector to reset your selection. Click at the end of the guide bar to reset all calculated impactor positions.

Pre-Requisites on the Headform Model

This tool can position pendulum headform and linear headform (Normal to Target positioning).

In both cases, a coordinate system at the center of the headform with the X axis pointing in the travel direction needs to be defined.

The velocity should be defined in the impactor model since this tool doesn’t generate it automatically.

Positioning Methods

Tangent to Trajectory

Figure 14.


Selecting this method positions the headform with the target location on the circular trajectory of the center of the head.

The Aiming Point can be either Target or Contact point.

The Z Level Method fixes the Z coordinate of the pivot of the headform. Per default, it is set to the H-Point Z coordinate (= Seat Reference Point Z coordinate in the Design Point metadata). It can be switched to User defined, and you can provide a value.

The Move back Angle is applied once the impactor position is calculated in order to avoid intersections with the instrumental panel.

The metadata defined in the selected Design Point entity is ignored and overwritten with the values calculated by this positioning method.

Figure 15. Tangent to Trajectory positioning


Normal to Trajectory

Figure 16.


Selecting this method positions the headform with the IP-normal at target location aligned on the X-Axis of the coordinate system at the center of the headform.

The IP-normal vector is determined with the surrounding elements at the target location.

A pivot node selection is not requested.

The Move back Distance is applied once the impactor position is calculated in order to avoid intersections with the instrumental panel.

The metadata defined in the selected Design Point entity is ignored and overwritten with the values calculated by this positioning method.

Figure 17. Normal to Trajectory positioning


Pivot/Angles

Figure 18.


Selecting this method positions the headform by moving the pendulum pivot to the given (Pivot X, Pivot Y, Pivot Z) location, and applying successively the V-Angle around the global Y axis and H-Angle around the transformed X-Axis. (X’)

The Move back Angle is applied once the impactor position is calculated in order to avoid intersections with the instrumental panel.

Since pivot and angles are directly given as input, the target point may not necessarily be on the trajectory of the headform.

The metadata defined in the selected Design Point entity is ignored and overwritten.

Figure 19. Pivot/Angles positioning


Target/Angles

Figure 20.


Selecting this method positions the headform by applying the H and V angles around the Target point location.

The pivot location is not an input and results from the application of both angles.

The Move back Distance is applied once the impactor position is calculated in order to avoid intersections with the instrumental panel.

Figure 21.


Automatic

Figure 22.


Selecting this method positions the headform according to the positioning parameters defined in the Design Point entity.

Figure 23.


Export Solver Decks

This tool enables you to export ready-to-run solver decks for all the impact locations.

In the IP Positioning Workflow, provide the information in the Export Parameters.

Figure 24.


The Main File is the user-defined main input deck containing the include structure of the final model (IP model, contacts, controls, boundary conditions, …)

Here is an example of a Main File for LS-DYNA:

Figure 25.


And here is an example for Radioss:

Figure 26.


Headform File should point to the headform model that the tool will define as an include in the Main File during the export of the decks.

The Output Directory is the location where all the solver decks for each impact location are written out.

During the export process, the tool generates an additional include file containing the transformations to apply on the impactor using the Transformation Type.

Example of positioning include file generated by the tool:

Figure 27. LS-DYNA


Figure 28. Radioss


Finally, the positioning file is automatically added as an include file in the Main File. The resulting model files for each impact location look as follows:

For LS-DYNA:
  • FMVSS201_L_8.k
  • fmvss201_pendulum_800mm_t-mm-s.k
  • Positioning_FMVSS201_L_8.key
For Radioss:
  • fmvss201_pendulum_800mm_t-mm-s.rad
  • FMVSS201_R_12_0000.rad
  • Positioning_FMVSS201_R_12_0000.rad