René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Wrong offset in 'element_beam_node_indexes'","articleBody":"\nAccoring to the [LS-DYNA® Database Binary Output Files](https://ftp.lstc.com/anonymous/outgoing/lsprepost/d3plot_database_manual/ls-dyna_database_Apr2020.pdf) Manual, Section `GEOMETRY DATA` (Page 18) the Array `IX2(6,1)` contains\n\n\u003e Connectivity, orientation node, two null entries, and the material number for each 2 node beam element.\n\u003e For some beam types the last two number contain the beam type and length to width ratio * 100 and length to height ratio * 100\n\u003e type = ix2(5,\\*) \u0026 0x3F\n\u003e width = 0.01 * length / (ix2(5,\\*)\u003e\u003e6\n\u003e height = 0.01 * length / ix2(6,\\*)\n\u003e Third node (orientation) may be \u003e 1e9 Contain flag 1e9 to indicate a spot weld\n\nMy interpretation of this is the array layout is this:\n\n- [N1, N2, N3, 0, 0, MAT_ID] for 2-Node-Beams\n- [N1, N2, N3, LW_RATIO_TYPE, LH_RATIO, MAT_ID] for some other Beams\n\nIn [Line 2426](https://github.com/open-lasso-python/lasso-python/blob/a9607eff8d397913a8834358e6450a5febcec8d8/src/lasso/dyna/d3plot.py#L2426) you subtract the FORTRAN_OFFSET (1) from all values of the array, but this is not correct. The offset should only be applied for N1, N2, N3 and must not be applied for LW_RATIO_TYPE, LH_RATIO. Otherwise the extraction of these values does not work (without having to add 1 again).\n\n```python\n# element_beam_node_indexes = d3plot.arrays[ArrayType.element_beam_node_indexes]\nbeam_type = element_beam_node_indexes[3] \u0026 0x3F\nbeam_width = 100 * L / (element_beam_node_indexes[3] \u003e\u003e 6)\nbeam_height = 100 * L / element_beam_node_indexes[4]\n```\n\nOne could also think of adding a new array with these values \n\n- `element_beam_node_indexes` containing `N1`, `N2`, `N3` and `TYPE` (all `integer` values)\n- `element_beam_dimensions` containing `WIDTH` and `HEIGHT` (all `float` values) \n\nIn [Line 2424](https://github.com/open-lasso-python/lasso-python/blob/a9607eff8d397913a8834358e6450a5febcec8d8/src/lasso/dyna/d3plot.py#L2424) you add the MAT_ID to the PART_ID (Array `element_beam_part_indexes`). Is this correct?\n\nKind regards\nFlorian","author":{"url":"https://github.com/FlorianFritz","@type":"Person","name":"FlorianFritz"},"datePublished":"2025-09-13T08:15:02.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/91/lasso-python/issues/91"}