PML in LS-DYNA
PML has been implemented in LS-DYNA for elastic, fluid and acoustic media, and may be used through one of the following cards:
- MAT_PML_ELASTIC (MAT_230), corresponding to MAT_ELASTIC (MAT_001)
- MAT_PML_ELASTIC_FLUID (MAT_230_FLUID), corresponding to MAT_ELASTIC_FLUID (MAT_001_FLUID)
- MAT_PML_ACOUSTIC (MAT_231), corresponding to MAT_ACOUSTIC (MAT_090)
- MAT_PML_ORTHO/ANISOTROPIC (MAT_245), corresponding to MAT_ORTHO/ANISOTROPIC_ELASTIC (MAT_002 and MAT_002_ANIS)
- MAT_PML_NULL (MAT_246), corresponding to MAT_NULL (MAT_009); to be used only with EOS_LINEAR_POLYNOMIAL or EOS_GRUNEISEN.
Please see the latest draft manual for the input format of each card.
Each PML material is meant to be placed next to — and absorbs waves from — a bounded domain composed of the material to which it corresponds. The material in the bounded domain near the PML should be linear, and the material constants of the PML should match those of the linear bounded material. To facilitate this, the input format of each PML material is largely similar to the corresponding linear material.
Some further requirements for the PML materials are:
- The PML material should form a parallelepiped box around the bounded domain, and the box should be aligned with the coordinate axes.
- The outer boundary of the PML should be fixed.
- The PML layer may typically have 5–8 elements through the depth.
- The PML material should not be subjected to any static load.