Example 10: Lack of Fusion *LFUS and *TPRE Example

Sample files for use with the examples are available from the Downloads page.

Expand the downloaded ZIP archive into a convenient directory from which to run Local Simulation inside the numbered directories.

Problem description

For this example, you will run commands inside directory 10.

This is an example of using the state variable card *LFUS and *TPRE to inspect the thermal history of two moving source simulations. The first simulation is the analysis of a single powder bed layer using the adaptive refinement methods described in Example 4. The second simulation is the analysis of a multilayer powder bed analysis using a moving heat source, using both layerwise and moving adaptivity mesh coarsening techniques.

For the single-layer moving adaptivity simulation, a moving heat source of 50 W moving at 1000 mm/s is applied on the top surface of a 1.0 mm × 1.0 mm × 12.7 mm substrate made of Ti-6Al-4V. A surface convection of 10.d-6 W/((mm2)°C) is applied on the top surface and all other faces are insulated. The *ADPM card is used to control the acceptable temperature gradients across an element for coarsening, using the default settings. The mesh and laser path are automatically generated using Local Simulation. The melting of three powder layers is simulated.

For the multilayer adaptivity simulation, a three-layer simulation is completed on the top surface of a 0.5 mm × 0.5 mm × 12.7 mm Ti-6Al-4V substrate, with a 25.d-6 W/((mm2)°C) top surface convection, also using a 50 W heat source and a scan speed of 1000 mm/s, with a 120 s interlayer dwell. Layerwise adaptivity is controlled on the auto-generated mesh using the *ADAP and *ADP1 cards. The *ADPM card is used to enable moving adaptivity.

For both simulations the *LFUS card is used with a value of 1600° C, to investigate lack of fusion. The *TPRE card is used to inspect the temperatures immediately prior to application of the heat source with the values of 690° and 1600° C, which are the stress relaxation and melting temperatures respectively.