AMBUILD

AMBUILD, Option, VAL1, VAL2, VAL3, VAL4
Specifies printer parameters for the build and other options in an additive manufacturing analysis.

SOLUTION: Additive Manufacturing

Option

Option:

LAYERT

—

VAL1 – Deposition-layer thickness.

VAL2 – Mesh height.

VAL3 – Error-checking flag. Set to 0 (default) or 1. Setting to 1 causes the application to omit error checks for consistent element size and elements spanning across layers.

SCAN

—

VAL1 – Hatch spacing.

VAL2 – Beam-travel speed.

TIME

—

VAL1 – Inter-layer dwell time. Default = 0.0.

VAL2 – Dwell-time multiplier for multiple parts on the build plate or number of repeated symmetry sectors in simulations with symmetry. Default = 1.0.

VAL3 – Heating step time for use with beam power option (AMBEAM,,POWER).

VAL4 – Scan time table.

PLATE	—	`VAL1` – Z-coordinate of the top of the build plate. Default = 0.0.
CHECK	—	`VAL1` – If YES, create the build-summary file but do not solve. Default = NO.
RTHFILE	—	`VAL1` – Name of the thermal-results file (including its path). Default = file.rth in the current working directory.
SSF	—	`VAL1` – Strain Scaling Factor. Default = 1.0.

Command Default

None. An Option label is required.

Notes

If using a layered tetrahedral mesh, specify the mesh height (LAYERT,VAL2). For Cartesian meshes, the mesh height is determined automatically.

When setting the error-checking flag (LAYERT,,,1), verify your model and results carefully. Using the flag may lead to improper setup of layers or boundary conditions.

The hatch spacing and beam travel speed are the average values used during the build.

The inter-layer dwell time (TIME,VAL1) is the span of time from the end of the deposition of a layer to the start of the deposition of the next layer. It includes the time required for recoater-blade repositioning and powder-layer spreading.

The dwell-time multiplier (TIME,,VAL2) accounts for more than one part being printed on the build plate, or it is used to reconcile build time in simulations using symmetry. For multiple parts on a build plate, if the additional parts are the same part as the one being simulated and are arranged in the same orientation on the build plate, the multiplier is the total number of parts. If different parts exist on the plate, the multiplier is an estimate of the time required to build the other parts relative to the part being simulated. In simulations with symmetry, the dwell-time multiplier is the total number of repeated symmetry sectors: 2 for half symmetry, 4 for ¼ symmetry, and so on.

The heating step time (TIME,,,VAL3) is used along with other defined process and geometric parameters (power, scan speed, hatch spacing, deposition thickness, superlayer volume) to set the time duration and magnitude of heat generation on new element layers. A value of 0 (default) sets the heating time to the minimum time step constraint. See General Options in the Thermal Analysis Guide. When power has been specified, you can alternatively enter SCAN in this field to set the heating time to the amount of time it would take to scan the volume of material in each element layer. With the SCAN option, the cooling between layers will still be the recoater time. Setting VAL3 = SCAN may give better temperature results at the end of the layer and is more stable across different mesh sizes. Note that the SCAN option will have a different end time of the simulation because the layer thickness adjustment for cooling will not be used.

The scan time (TIME,VAL4) represents the amount of time it takes to scan a real layer. By default, the scan time will be determined from each layer’s cross-sectional area and other process parameters. When specified, it must be defined as a table with times specified on the Z primary variable. Times that are averaged or interpolated from the table should not include recoating time and will be adjusted to account for superlayer size compared to the deposition thickness.

When specifying the name of the thermal-results file (RTHFILE,VAL1), omit the .rth extension. The program also looks for the thermal.build file in the same path.

The strain scaling factor (SSF,VAL1) scales the thermal strains in the structural portion of thermal-structural simulations by the specified value.

This command is also valid in PREP7.

For more information, including a list of the elements and commands used in an additive manufacturing analysis, see Additive Simulation in Mechanical in the LPBF Simulation Guide.

Menu Paths

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