True Section: Displaying the Actual Beam Cross-Section

True Section: displaying the actual beam cross-section

If a .ZTF file from PRIMER 9.2 or later has been read, section information will be available for beams which, if this option is selected, allows them to be drawn using their "true" section shapes.

For "Integrated" beams with explicit section dimensions this is simple, and the actual dimensions are used.

For "Resultant" beams where only Area, Ixx and Iyy properties are available then a thin-walled rectangular section that matches these properties is synthesized. This should be approximately correct, but obviously it cannot represent I beams or rectangular sections with varying wall thicknesses, but it should give a reasonable representation of beam dimensions. If you use inconsistent or impossible properties you may get some strange looking sections!

If True Sections are being plotted D3PLOT can not calculate a size of shape for discrete beams. By default discrete beams are drawn as a sphere with a diameter that is 1% of the model's longest dimension (in model space units). This size can be adjusted if necessary.

True Section: Recommended modelling practices

There are a number of modelling choices that can be made when defining beam elements which can affect how they are displayed in D3PLOT. The following practices are recommended for the best visualisation of results in D3PLOT.

• Define the beam orientation using a unique 3rd node for each beam rather than the _ORIENT option.
• Set NREFUP=1 on the *CONTROL_OUTPUT keyword. This will update the position of each 3rd node through the analysis, allowing D3PLOT to display the correct rotation.
• If the _OFFSET option is used to define an offset, ensure that it is specified in the positive direction of the orientation vector. If it is specified in the opposite direction the beam offset can be shown as flipped in D3PLOT (the Ansys LS-DYNA analysis will still be correct).