Specifying Surfaces, Integration Points and Nodal Locations for Data Extraction
Specifying Surfaces, Integration Points and Nodal Locations for data extraction
Specifying Surfaces and Integration Points
From T/HIS 12.0 onwards, the syntax for specifying which surface or integration point to read data from for Shells, Thick Shells and Beams has changed. These options are now appended to data extraction as follows.
Shells and Thick Shells
| extra word #1 | extra word #2 | notes |
| surface | top | If no surface option is specified then the default (middle) surface will be used. |
| middle | ||
| bottom | ||
| n |
| e.g. | shell 99 stress xx tag curve_1 |
| (read x stress for shell 99 middle surface) | |
| shell 99 stress xx surface top tag curve_1 | |
| (read x stress for shell 99 top surface) | |
| shell 99 stress xx surface 3 tag curve_1 | |
| (read x stress for shell 99 layer 3) |
Beams
| extra word #1 | extra word #2 | notes |
| ipoint | n | Specifies the beam integration point to read data from |
| e.g. | beam 99 stress x ipoint 1 tag curve_1 |
| (read axial stress for beam 99 integration point 1) |
Specifying in-plane integration points for Shells and Thick Shells
In recent versions of Ansys LS-DYNA it is possible to write out data at multiple in-plane integration points for fully integrated Shells and Thick Shells for each through thickness layer.
For fully integrated solid elements data can also be written out for all 8 integration points.
By default T/HIS will automatically read the average value for each element. If the element isn't fully integrated then the data for the 1st point will be used, if it is fully integrated and has multiple integration points then the average value will be calculated.
| extra word #1 | extra word #2 | notes |
| ipoint | n | Specifies the in-plane integration point to read data from. If this option isn't specified then the surface centre value will be selected. If the element is fully integrated then the average value will be calculated from all 4 in-plane values |
| e.g. | shell 99 stress xx tag curve_1 |
| (read x stress for shell 99 middle surface, centre value) | |
| shell 99 stress xx ipoint 1 tag curve_1 | |
| (read x stress for shell 99 middle surface in-plane integration point 1) | |
| shell 99 stress xx surface middle ipoint 1 tag curve_1 | |
| (read x stress for shell 99 middle surface in-plane integration point 1) | |
| shell 99 stress xx surface 5 ipoint 2 tag curve_1 | |
| (read x stress for shell 99 layer 5 in-plane integration point 2) |
Specifying integration points for Solids
In recent versions of Ansys LS-DYNA it is possible to write out data at all 8 integration points or fully integrated solid elements.
By default T/HIS will automatically read the average value for each element. If the element isn't fully integrated then the data for the 1st point will be used, if it is fully integrated and has multiple integration points then the average value will be calculated.
| extra word #1 | extra word #2 | notes |
| ipoint | n | Specifies the solid integration point to read data from. If this option isn't specified then the centre value will be selected. If the element is fully integrated then the average value will be calculated from all 8 values |
| e.g. | solid 99 stress xx tag curve_1 |
| (read x stress for solid 99 centre value) | |
| solid 99 stress xx ipoint 1 tag curve_1 | |
| (read x stress for solid 99 integration point 1) |
Selecting data at element nodal positions
In recent versions of Ansys LS-DYNA it is possible to write out data for Solid, Shells and Thick Shells that has been extrapolated from the integration points to the elements nodes.
For Shells the values at all through thickness layers can be extrapolated to the nodes. For Thick Shells the bottom surface values are extrapolated to nodes 1-4 and the top surface values are extrapolated to nodes 5-8.
| extra word #1 | extra word #2 | notes |
| node | n | Specifies the element node number to read data for |
| e.g. | shell 99 stress xx node 3 |
| (read x stress for shell 99 middle surface extrapolated to node 3) | |
| shell 99 stress xx surface 5 node 1 tag curve_1 | |
| (read x stress for shell 99 layer 5 extrapolated to node 1) | |
| tshell 99 stress xx node 7 tag curve_1 | |
| (read x stress for thick shell 99 top surface extrapolated to node 7) | |
| solid 99 stress xx node 4 tag curve_1 | |
| (read x stress for solid 99 extrapolated to node4) |