Introduction

The StressCheck Results, or simply Results, option provides access to the various output classes, including Error Estimation, Plot, Min/Max, Points, Resultant, Properties, and Fracture Mechanics. The Results dialog provides a tab for each available output class. These tabs are ordered in a way consistent with a typical model post-processing sequence: assess estimated relative error in energy norm, plot deformed shape and/or stress contours, extract maximum stresses and/or strains, extract stress/strain gradients across model boundaries, compute stress resultants, etc. All results computations are performed “live”, meaning there is no pre-determined or pre-computed output data.

The Results dialog can be displayed by selecting “Results” from the Main Menu “Edit” pulldown menu, or by selecting a Results class such as Error Estimation, Plot Solution, Extract Min/Max/Avg, etc., from the Main Menu “Class” pulldown menu. Alternatively, the Results dialog may be activated by selecting the “View Results” icon in the Main Toolbar or in the Simulation Pane via Results (Figure 1).

At the top of the Results dialog are the C/A/O/M combo-boxes for selecting the desired combination of Action (e.g. Select), Object (e.g. Any Element), and Method (e.g. Selection). By default, directly below the C/A/O/M combo-boxes is a listbox containing all available solutions for post-processing, ordered by Solution ID(s) and corresponding Run number(s). In the center of the Results dialog are Solution ID and Run specification options, as well as computation/extraction options which relate to the specific category of output chosen with the tab. Note that the selection of a solution from the listbox will automatically populate the Solution ID combo-box and Run specification field(s).

At the bottom of the dialog is a set of buttons which are used to invoke a command (e.g. Accept, Plot) and a Settings pane to allow the storage/retrieval of results extraction settings. NOTE: in previous releases, three subtabs (Input, Settings and File) were available within the Results dialog. These options have been replaced by the Settings pane and import/export options for results extraction settings.

Standard Engineering Functions

To simplify the notation used for the computation of standard engineering data such as displacements, strains and stresses, symbols were introduced to represent these common engineering functions. The following prefixes indicate the type of standard engineering function:

• “U”: displacements (u)
• “E”: normal strains (ε)
• “G”: shear strain (γ)
• “S”: normal stress (σ)
• “T”: shear stress (τ)

For example, “Sx” represents the normal stress σ_x and “E1” represents the 1st principal strain ε₁. The user may select any standard engineering function symbol from the function list during post-processing. In StressCheck, standard engineering functions are supported for the output classes Plot Solution, Extract Min/Max, and Extract Points.

Learn more about Standard Engineering Functions.

Formula & Calculator Options

When a standard engineering function is not sufficient, additional options to combine standard engineering functions are available.

Formula Post-Processing

Using the Formula (“Fmla”) option, any mathematical expression containing the standard engineering functions (defined via Edit > Formulae…) can be computed for a given solution. For example, the user may wish to compute the following check for the onset of plasticity:

M1 = Seq/Syield – 1,

where Syield is a parameter value representing a yield stress, and Seq is the von Mises stress σ_eq. To use this formula in a post-processing computation, the user will select “Fmla” as the function name, and then “M1” as the formula name.

Calculator Post-Processing

Using the Calculator (“Calc”) option, any mathematical expression containing standard functions can be computed for any arbitrary combination of solutions. This technique differs from the Formula option in that standard functions from multiple runs/solutions can be used, whereas only functions from a single run can be used with the Formula option. For example, the user may wish to compute the following superposition of directional stresses for two solutions/runs:

1/2*Sx_1 + 2*Sx_2,

where Sx_1 is the normal stress σ_x for the first solution/run, and Sx_2 is the normal stress σ_x for the second solution/run. To use the Calculator option in a post-processing computation, the user will select “Calc” as the function name. Then, the user may indicate the desired Solution ID(s), Run(s) and an expression containing standard functions. Formulae (i.e. “Fmla”) and Calculator (i.e. “Calc”) options are supported for the output classes Plot Solution, Extract Min/Max, and Extract Points.

Learn more about Formula & Calculator Options.

Graph

For all output classes except the Plot and Settings classes, a graph pane designed to present the results of most post-processing computations appears after clicking on the Accept button in the Results dialog (Figure 2). The graph pane results may be copied/exported in a variety of formats.

To learn more about the graph, visit the Graph Overview.

Settings Pane

The Settings pane provides an interface that will enable the user to record the current Results dialog control settings for later use. The results extraction settings are stored in the database in alphabetical order, and are therefore also processed in alphabetical order when extracting in an automation setting. It is important to name these records in such a way that the results extractions will be performed in the desired order.

• When saving a new results extraction setting, the user should supply a unique name in the combo box provided (e.g. “S1Max”) to identify each record of settings. Use the Save button in the Settings pane to save the current settings in a record to be identified by the name provided. If the name provided matches an existing record, the existing record will be replaced.
• To retrieve a previously stored results extraction setting, simply select the desired name from the combo box. The user interface will automatically be updated to reflect the settings stored in the chosen record. Then, click on the Accept/Plot button to extract/plot that results extraction setting.
• Use the Delete button to remove the results extraction setting identified by the name in the combo box.
• Use the Purge button to remove all results extraction settings from the database.

Export a Results Extraction Settings File

To export a list of saved results extraction settings for later use, use File > Export and select the “StressCheck Settings file (*.scsettings)” filter. Then, provide a name representing the list of results extraction settings. Note: all solution settings in the current StressCheck project will also be exported to the .scsettings file.

Import a Results Extraction Settings File

A StressCheck settings file may be imported to another StressCheck project by using File > Import and selecting the .scsettings file. The list of results extraction settings should be available in the Settings dropdown. Note: any solution settings stored in the imported .scsettings file will also be available in the Solve dialog’s Settings dropdown.

Results Output

Below are the results output types supported in StressCheck, and accessible via the Results dialog tabs.

Error Estimation

To access the Error Estimation output class, from the Class menu select Error Estimation or select the Error tab in the Results dialog. The options under Error Estimation provide for the assessment of the relative error in energy norm for all elements, strain energy error for one or more elements, and error indicator computations based on user-defined criteria.

To learn more about the error estimation outputs, visit the Error Estimation Overview.

Plot Solution

To access the Plot Solution output class, from the Class menu select Plot Solution or select the Plot tab in the Results dialog. The options under Plot Solution provide for the computation and display of model deformation, displacement contours, strain contours, stress contours, etc. in the Model View. Contours may be plotted without (default) or with elemental averaging.

With the release of StressCheck v12.0, right-click context menu options are available for controlling the display of plotted information (e.g., engineering function, fringe contour range, color map, etc.). For more information, refer to Context Menu Overview.

To learn more about the plot solution outputs, visit the Plot Solution Overview.

Extract Min/Max

To access the Extract Min/Max output class, from the Class menu select Extract Min/Max or select the Min/Max tab in the Results dialog. The options under Extract Min/Max provide for the computation of the location(s) and magnitude(s) of minimal and maximal values of displacement, strain and stress for a solution or a sequence of solutions.

To learn more about the extract min/max outputs, visit the Extract Min/Max Overview.

Extract Points

To access the Extract Points output class, from the Class menu select Extract Points or select the Points tab in the Results dialog. The options under Extract Points provide for the computation of pointwise or averaged data at user-defined locations, in user-selected points or nodes, along user-specified element edges or geometric curves, and within user-specified element faces or geometric surfaces.

To learn more about the extract points outputs, visit the Extract Points Overview.

Resultant

To access the Resultant output class, from the Class menu select Resultant or select the Resultant tab in the Results dialog. The options under Resultant provide for the computation of equilibrium over the boundaries of one or more elements, or stress resultants (i.e. integration of tractions) across one or more element edges (2D) or faces (3D). Note: resultant computations are also supported for Contact Zones for assessment of load transfer in multi-body contact solutions.

To learn more about the resultant outputs, visit the Resultant Overview.

Extract Properties

To access the Extract Properties output class, from the Class menu select Extract Properties or select the Properties tab in the Results dialog. The options under Properties provide for checking the distortion, and the area or volume of the model before and after the finite element solution was obtained.

To learn more about the extract properties outputs, visit the Extract Properties Overview.

Fracture Mechanics

To access the Fracture Mechanics output class, from the Class menu select Fracture Mechanics or select the Fracture tab in the Results dialog. The options under Fracture provide for computation of Mode 1 and Mode 2 (K1 and K2) stress intensity factors (SIFs) in linear elastic fracture mechanics, for two- and three-dimensions. It also has the capability of computing the J-integral and the T-Stress for two- and three-dimensional problems. Note: for the computation of SIF or J-integral distributions in 3D, refer to the Extract Points output class.

To learn more about the fracture mechanics output, visit the Fracture Mechanics Overview.

Settings (Convergence Criteria)

The Convergence Criteria tab in the Results dialog is used for defining convergence criteria records that will be used in the context of the Solution dialog. These convergence criteria records identify extraction operations which will be performed at the completion of each finite element solution in order to test whether the solution is of sufficient quality to be used as the basis for engineering decisions.

To learn more about setting convergence criteria for the Solve dialog’s Solution dropdown, visit the Convergence Criteria Overview.