baspl++ Tools

1. History XY Plots

1.1. The History XY Plot Widget

The History XY Plot tool is an extension to baspl++ offering a set of standard computational mechanics xy data extraction and graph visualization, such as graphs displaying non-linear solid mechanics behaviour. The History XY Plot tool is targeted at supporting B2000++ model databases, and It can be operated interactively or with scripts, which can be generated automatically from interactive sessions. The History XY Plot tool works seamlessly with all other baspl++ viewing functions. An example of a typical non-linear solid mechanics load history plot is given below:

The History XY Plot tool is based on a B2000++ specific data extraction, creating pairs of (x, y) values to be rendered with the Graph and Curve classes. Data extraction functions of the x- and y-columns of data currently include

  • Reaction forces

  • Sampling points of specific elements

  • Degrees of freedom of specific nodes

  • Distance between 2 deformed nodes

  • Attributes and cycles

The extraction functions can be applied to the x- or to the y-axis (columns). An example of a typical non-linear solid mechanics load history plot is given below, where the data extraction function for the x-axis is the attribute TIME, and for the y-axis the reaction forces:

Example History XY plot: Reaction force of compresses structural panel vs. time for a ramp function type dynamic loading.

Figure 1. Example History XY plot: Reaction force of compresses structural panel vs. time for a ramp function type dynamic loading.


The History XY Plot tool is launched from the baspl++ top-level menu bar by selecting History XY-Plots for Nonlinear Analysis... from the Tools menu:

upon which the History XY Plot widget appears:

The selected database (here q9.b2m) now appears in the list of active databases, with a colour assigned to it (blue). Graphs assigned to this database will appear in this colour. The blue-grey background means that this database is active, i.e. selections pertain to this database.

History XY Plot will now create or try to create a graph with the default settings, i.e. the load factor or time on the x-axis and the reaction forces on the y-axis (note: The reaction forces are the forces created by pushing the structure in a certain direction - this type of plot may not work with other types of loadings on a structure!).

1.2. Detailed Description of the History XY Plot Widget

The Extraction selectors:

  • Extraction method for X values specifies which data to extract for the x-axis.

  • Extraction method for Y values specifies which data to extract for the y-axis.

The General tab:

  • Case extracts values for a given 'load' case.

  • Restrict to stage restricts the extraction to a stage. See the B2000++ USer Manual for details about cases and stages.

  • Restrict to cycles specifies witch computational cycles are to be extracted. By default the tool tries to extract all cycles found for the current stage or case.

  • Restrict to subcycles specifies witch computational -sub-cycles are to be extracted. By default the tool tries to extract all cycles found for the current stage or case (if any).

The X/Y values tab parameters depend on the extraction method.

  • Common parameters:

    • Scale factor specifies the factor by which the x-axis values are to be scale. Default is 1.0

  • reaction forces extracts the sum of selected reaction forces:

    • Only non-zero EBC specifies that, when checked, only the sum of all reaction forces created by pushing the structure in a certain direction will be included (default).

    • Include NBC specifies that, when checked, the sum of all NBC's pertaining to the current selection, will be included.

    • Nodesets allows for restricting the extraction of reaction forces to certain nodes only, defined by B2000++ node sets.

    • Cs specifies a optional transformation to be applied to the sum of reaction forces.

    • Component specifies the component to be extracted. Default is amplitude.

  • sampling points extracts values of sampling points of a given element:

    • Branch specifies the branch number for which the sampling point values will be extracted. Default is 1.

    • Element specifies the element number for which the sampling point values will be extracted. Default is 1.

    • Layer specifies the layer number (relative to the element) from which the value are extracted. Default is None, meaning that the aggregate value of all layers will be extracted.

    • Sampling point specifies the sampling point number (relative to the element) from which the value are extracted. Default is None, meaning that the aggregate value of all sampling points will be extracted.

    • Generic name specifies the generic name of the sampling point field to be selected.

    • Compname specifies the sampling point component to be extracted. It depends on the type of sampling point and baspl++ will present a list with all available components.

    • Aggregate function specifies the aggregate function to be applied when multiple values are found: max means that the maximum of all values will be selected. main means that the minimum of all values will be selected. avg-abs computes the average from the absolute values at all sampling points. Default is max.

  • dof extracts values of DOF'S (degrees-of-freedom) at a given node:

    • Branch specifies the branch number for which the sampling point values will be extracted. Default is 1.

    • Element specifies the element number for which the sampling point values will be extracted. Default is 1.

    • Generic name specifies the generic name of DOF field to extracted. Default is DISP (the B2000++ default DOF field name).

    • Compname specifies the component to be extracted. Default is amplitude.

    • Cs specifies the coordinate system in which the DOF's are extracted. global mean global coordinate system (default). local means (node) local coordinate system, if any.

  • distance extracts the distance between 2 nodes as a function of the load history:

    • Branch specifies the branch number of which either node will be selected Default is  1.

    • Node specifies either node number.

  • attribute extracts various global attributes, such as TIME:

    • Key specifies the attribute name.

    • Operator specifies the binary operator to be applied to the first and second key. The operator is only active if a second key is defined.

    • Second key specifies the second attribute name.

    • Accumulate specifies if value shall be accumulated, if checked.

    • Cs specifies the coordinate system in which the DOF's are extracted. global mean global coordinate system (default). local means (node) local coordinate system, if any.

  • cycle extracts the computational cycle.

  • subcycle extracts the computational sub-cycle. Note that, by default, B2000++ does not store subcycle datasets on the database.

  • aggregate extracts the maximum, absolute maximum, minimum, or absolute minimum value of a field.

    • Generic name specifies the generic name of the field to be aggregated.

    • Compname specifies the component to be extracted. Default is  1.

    • Aggregate function specifies the aggregate function to be applied when multiple values are found: max means that the maximum of all values will be selected. min means that the minimum of all values will be selected. max-abs means that the maximum of the absolute values will be selected. min-abs means that the value nearest to 0 will be selected. Default is max.