Xtract

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Abrupt changes in deformation plots

Version: All

The issue may be 'complex evaluation' in Xtract. When Xtract presents a wave represented as a complex load case you have to specify the phase of the wave. Here Xtract has several options;

  • True minimum
  • True maximum
  • Absolute minimum
  • Absolute maximum
  • Phase

Default when you make a combination with a complex load case is absolute max.

This means that Xtract will find the phase that gives absolute max length of the displacement vector at all nodal points (for result selection DISPLACEMENTS ALL) The phase giving absolute max may vary from node to node and hence there is no continuity in the displacement plot for such a combination.

To get a plot that is easier to grasp you may make a combination where all the nodal results are for the same phase of the wave. This means making a combination with the Phase e.g. 0 deg. The phase is the third parameter in the combine command or you select it in the combine dialogue.

In your case:

combine "amec-combination-input" max "Nodes" "Displacement" "ALL" "1" "29" "1" 1.3 "1" "31" "1" 1.3 "1" "32" "1" 1.3 "1" "33" "1" 1.3 "1" "2" "1" 0.7
combine "amec-combination-input" 0 "Nodes" "Displacement" "ALL" "1" "29" "1" 1.3 "1" "31" "1" 1.3 "1" "32" "1" 1.3 "1" "33" "1" 1.3 "1" "2" "1" 0.7

The fact that Xtract evaluates the results node by node may be confusing because the results may not be comparable from one node to the next. On the other hand the absolute max value for each node is often what you are after..

Keywords: displacement deformation jump fluctuating wrong wave change

Please see the attached document Xtract1.

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Can’t start Xtract 6.0-01 due to missing or not supported license version

Can’t start Xtract 6.0-01, with either of the following error messages:

ERROR: While checking out a license. License server system does not support this version of this feature.

or

Command disabled due to missing license feature even with Flexlm / License Manager version v11.17 installed.

The issue is due to a wrong version date in Xtract 6.0-01 and may occur if the license expires before 2021.1231. An updated version will be released shortly.

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Combination of Individual Result Cases and Plots

It is possible in Xtract to combine the results for different stress results for a single loadcase.

Say you want to determine the principle stress range of P1 and P2 for a single loadcase. 

Plot P1

Results-Scan - Maximum, give it a name

Plot P2

Results - Scan - Minimum, give it a name

then you can combine results through Results - Combine - P1scan and P2scan with a factor if you like.

Also useful for calculating different variations of the VM stress, some codes specify the VM stress calculation, and doing any other general combination or math on an individual result.

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Combine/Scan dialogs don't open for Element average results

Version: 4.1-02

After selecting any component of any attribute in position Element average the Scan and Combine dialogs don't open.   In case of Combine workaround is: Select any component of any attribute other than Element average. Open combine dialog. Select desired Element average component.   In case of scan workaround is: (Workaround described for combine does not work since the component currently selected when opening the scan dialog is the one to be scanned and this cannot be changed.) Workaround is to paste in a command or read a command input file.

Note: The link below from status list also include the same information.

https://sesam.dnv.com/status/Xtract/Xtract.html?id=XTRACT_26-APR-2013_2.

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Display of beam elements from Equipment vertical mass option (Presel/HydroD/Xtract)

The display of beam elements from the equipment vertical mass option is different in Presel, HydroD and Xtract.

Presel and HydroD will show the "vertical mass" beam elements as beam 'tents', i.e. without eccentricities, in the same way as for the option "beams and mass" from equipments.

Xtract will show the vertical beam elements, i.e. with eccentricities, when the beam cross section is shown. In wireframe mode of beam elements, the eccentricities are not shown. The beam elements are shown in the same way as for the option "beams and mass" from equipments.

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Error opening Xtract.MLG when starting Xtract

When Xtract opens through “Start > All Programs > DNV Software > Applications > Xtract V4.1-02” then Xtract will open a log file (Xtract.jnl) plus some other working files in the location specified in the "Start in" field of the Xtract shortcut. By default, the "Start in" is C:\Users<user account>\Xtract. 

If you do not have write access to this "Start in" folder, then Xtract will not start, but instead report two error messages:  Error opening Xtract.MLG" followed by "OPERATING SYSTEM MESSAGE NO.: 9

Please check whether you can access the folder defined in "Start in" (use Right click, Properties to view "Start in) and that you have write privileges to it. 

If you get these two error messages when you start Xtract, please change to a different folder you have write access to, i.e. %temp% (your default temporary folder).  

Note: when you open Xtract from GeniE, Sesam Manager or any other program, then the log file will be opened from the folder where the results file, opened by Xtract, is found and Xtract will not report this error.

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How to select and save to file result case or component using line-mode commands?

Here are some proper variants of the command after having selected an attribute by the “result select ...” command:

result save "C:\Temp\Table1.txt" coords components resultcases – saves all components for all resultcases and including coordinates for the current attribute

result save "C:\Temp\Table2.txt" components resultcases – saves all components for all resultcases for the current attribute

result save "C:\Temp\Table3.txt" coords components  – saves all components including coordinates for the current attribute

result save "C:\Temp\Table4.txt" coords – saves current component of the current attribute including coordinates

“ccords”, “components” and “resultcases” are keywords and not parameters. The manual says page 5-2:

• Commands (keywords and parameter words) are in the command description written in normal font while parameters that can take different values are written in *italic *font.

• Brackets are used for optional input: text

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Material properties of boundary conditions are displayed

Version: All

When color coding material properties, if the model has spring boundary conditions, each spring will be color coded and displayed in the legend.

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Results in truss elements

Truss members are a somewhat special beam member in Sesam. Truss members can be analysed as part of a normal linear structural analysis or as part of a tension-compression analysis (e.g. if the truss members have been set to tension- or compression-only). While they are beam members, the results are shown slightly different compared to normal (non-truss) beam members.

In GeniE's result presentation normal beams will only show forces. However, truss members will not show the forces in GeniE and Xtract, but stresses. As such, if you want to view the results of the truss members, you will need to inspect the stress along the member. You are able to inspect the truss member results via the Results view in GeniE or via Xtract. The truss axial stresses are available via G-STRESS > sigxx. The force can then be easily computed using the cross-sectional area of the member.

No code check is available for truss members.

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Unable to start Xtract

This message may appear when, for example, GeniE or DeepC is trying to start Xtract.

Please check if Xtract is installed on your computer. The default installation path is C:\Program Files (x86)\DNVS\Xtract\Bin and C:\Program Files\DNVS\Xtract\Bin depending on your Operating System version. If it’s not there, then please download it from the Sesam Downloads.

Also, please make sure that you install Application version manager (AVM) on your computer which helps programs to locate the .exe files.

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Why is the Models, Results and or Sets tab not shown?

Version: 4.1-02

Symptoms:

One, more or all of the tabs on the left hand side may be hidden after opening a model in Xtract.

Cause:

The tabs can be hidden/closed by pressing on the red 'x' (close) button in the top right of the tab. This will take away the tab from the view.

Solution:

To get back all tabs, go to the Window-menu and click Database. This will hide all tabs. After this, go to the Window-menu again and click Database again. This will show all tabs again, including the ones that were hidden earlier.

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