Machining and Material Removal Process

The removal of material is simulated using progressive element activation in a structural or a thermal analysis. The cross-section of the bead of the material being removed is assumed to be rectangular. The following steps are required to define the removal process completely:

• Define the motion of the nozzle in an event series. The event series must have a least one field that defines the “on/off” state of the tool. Optionally, the event series can also define the varying height and width of the cutting operation, and the local direction vector $z_1$ , that defines the orientation of the tool, in five additional fields.
• Create a table collection with a name that begins with "ABQ_AM". The table collection must contain parameter tables of types "ABQ_AM_MaterialRemoval" and "ABQ_AM_MaterialRemoval_Bead".
• In the parameter table of type "ABQ_AM_MaterialRemoval", include a reference to the event series for the cutting tool motion.
• In the parameter table of type "ABQ_AM_MaterialRemoval_Bead", define the process parameters, such as the height and width of the bead. If the height and the width are both set to zero, Abaqus assumes the height to be equal to the average height of a finite element in the element set referenced from the progressive element activation and the width is large enough to cover the entire element set.
• Optionally, add a parameter table of type "ABQ_AM_MaterialRemoval_VariableBeadSize" to define the field positions in the event series that define the height and the width of the material removal tool’s cross-section.
• Optionally, add a parameter table of type "ABQ_AM_MaterialRemoval_5AxisStrategy" to define the field positions in the event series that define the three components of the local direction vector $z_1$ of the tool.
• Optionally, define a parameter table of type "ABQ_AM_MaterialRemoval_Advanced", to specify advanced settings for the element deactivation process.
• Refer to the table collection in the progressive element activation.

A dedicated collection of parameter table, property table, and event series types is available to include all of the definitions required by special-purpose techniques for additive manufacturing. You can use the abaqus fetch utility to obtain the file containing all of the type definitions of parameter tables, property tables, and event series required by the special-purpose techniques for additive manufacturing as follows:

abaqus fetch job=ABQ_am_special_purpose_types.inp

*EVENT SERIES TYPE, FIELDS=4, NAME=MaterialRemoval_5AxisStrategy
"On and Off", Dimensionless,
"ES field ID for normal vector componet x", L
"ES field ID for normal vector componet y", L
"ES field ID for normal vector componet z", L
EVENT SERIES, NAME=event series name, TYPE=MaterialRemoval_5AxisStrategy
t1, x1, y1, z1, 1, Z11x, Z11y, Z11z
t2, x2, y2, z2, 1, Z12x, Z12y, Z12z
...
TABLE COLLECTION, NAME="ABQ_AM_table_collection_name"
PARAMETER TABLE, TYPE= "ABQ_AM_MaterialRemoval"
event series name
PARAMETER TABLE, TYPE="ABQ_AM_MaterialRemoval_Bead"
"X", "Y", or "Z", bead height, bead width, activation offset, "Below" , "Middle", or "Above"
PARAMETER TABLE, TYPE="ABQ_AM_MaterialRemoval_5AxisStrategy"
"True" or "False", 2, 3, 4
PARAMETER TABLE, TYPE="ABQ_AM_MaterialRemoval_Advanced"
"Full" or "Partial", min volume fraction threshold for partial deactivation, 
max volume fraction threshold for partial deactivation, 
volume fraction threshold for full deactivation, update orientation, element subdivision order
...
ELEMENT PROGRESSIVE ACTIVATION, NAME=activation name, ELSET=element set name
...
STEP
STATIC or HEAT TRANSFER
...
ACTIVATE ELEMENTS, ACTIVATION=activation name
"ABQ_AM_table collection name"
...