The exercise begins with reading in the results and model data from file into FEMVIEW. A series of graphs are then produced to show the main features of the graphing module. Finally users are asked to generate particular displays, to consolidate their knowledge of this section.
Step 1 |
Read results data and enter FEMVIEW
UTILITY READ VIEWDATA TRANS1.FVI FEMV TRANS1 |
Display the full mesh with shrunken elements
VIEW OPTIONS SHRINK;VIEW MESH LABEL MESH NODES |
The model consists of ten QU8 elements and four 3 noded beams |
Step 2 | Look at the loads |
The model contains two loadcases : the first CONDUC has TEMP values varying with time from time=0 (step 0) to time=20 (step 46), seconds THERMO is a static loadcase, and has values of THERM1 and THERM2 |
UTILITY TABULATE LOADCASES
Figure 11.1: Model with node labels
Step 3 |
Plot a graph of temperature against time for certain nodes. A loadcase can be selected either by loadcase name or loadcase name and increment. A range of loadcases can be selected by specifying the increment range, or the time range.
First we select the required loadcase and step range. |
RESULTS LOADCASE CONDUC 0 TO CONDUC 46
The select the required attribute. |
RESULTS NODAL TEMP
Present the graph for node 2.
PRESENT GRAPH NODES 2
If desired we can present a graph for several nodes.
PRESENT GRAPH NODES 2 53 4 |
Step 4 | Plot a graph of temperature against time for certain elements. |
The temperatures also exist as element results, which we select.
RESULTS ELEMENT TEMP PRESENT GRAPH ELEMENT 2 9 10 11 |
It can be seen that the mean value for each element is plotted. We can change
the way the one value for each element is calculated.
RESULTS RANGE EL-RESULT MAX DRAWING DISPLAY |
We have complete control over which value for each element is graphed. |
PRESENT GRAPH ELEMENT 9 MIN 9 MAX 11 NODE 1 11 NODE 2 11 NODE 3
Step 5 |
We could have used PRESENT GRAPH PROMPT instead for graphing of element nodal
temperature against time for certain nodes (e.g. node 53).
PRESENT GRAPH PROMPT LOADCASES CONDUC 0 TO CONDUC 46 1 ELEMENT TEMP 10 NODE 53 |
Specify the limits to the axes.
PRESENT OPTIONS GRAPH AXES XMIN 0 XMAX .1 YMIN 20 YMAX 28
You could select a smaller range of loadcases.
RESULTS LOADCASE CONDUC BELOW .1
EYE FRAME
Label the points on the graph.
PRESENT OPTIONS GRAPH POINTS LABELS
You can use the cursor to get feedback on values anywhere on the graph.
PRESENT OPTIONS GRAPH FEEDBACK .336 .481
Swap the graph axes.
PRESENT OPTIONS GRAPH AXES SWAP
Clear the previous setting.
RESULTS STACK CLEAR PRESENT OPTIONS GRAPH AXES SWAP; PRESENT OPTIONS GRAPH POINTS LABELS OFF; VIEW MESH |
Step 6 | The model also contains a static loadcase "THERMO" with two nodal attributes "THERM1" and "THERM2". Plot a graph of these temperatures against distance along two lines of nodes: |
The line of nodes along the top edge, and the line of nodes along the bottom edge.
First of all we construct the required lines, giving them suitable names to be saved under.
CONSTRUCT LINE NODES TOP_EDGE THROUGH 24 2
CONSTRUCT LINE NODES BOT_EDGE THROUGH 4 1
Select the required loadcase and results attributes
RESULTS LOADCASE THERMO
RESULTS NODAL THERM1
Present the graph along both of the lines.
PRESENT GRAPH LINE TOP_EDGE BOT_EDGE
Step 7 | Display more than one attribute on the same graph. |
We first add the current attribute to the results stack.
RESULTS STACK ADD
Then we select the second attribute and force the graph to be redrawn.
RESULTS NODAL THERM2
DRAWING DISPLAY
You can specify limits to individual axes.
PRESENT OPTIONS GRAPH AXES 1 YMAX 1400;
PRESENT OPTIONS GRAPH AXES 2 YMIN 200
Change the size and position of the graph on the screen.
PRESENT OPTIONS GRAPH RESIZE .396E-1 .804 .816 .203
Return to the original settings.
PRESENT OPTIONS GRAPH RESIZE FRAME;
EYE FRAME
Specify that a single axis is used.
PRESENT OPTIONS GRAPH AXES SINGLE
You can shift the graph on the screen and zoom out by a factor.
EYE SHIFT .850 .294 .850 .378
EYE ZOOM FACTOR .8
Or zoom in on a particular bit of the graph.
EYE ZOOM IN .479 .558 .694 .465
Figure 11.2: Superimposed Graphs
Step 8 | Now we want to plot a graph of one results attribute against another. |
We can do this using the command PRESENT GRAPH RESULTS. Therefore, to display a graph of THERM2 against THERM1 for the nodes in line "TOP_EDGE", use:
EYE FRAME;
PRESENT GRAPH RESULTS
NODAL THERM1
1
NODAL THERM2
LINE(S)
TOP_EDGE
THERMO
We can do the same for both lines, this time using PRESENT GRAPH PROMPT.
PRESENT GRAPH PROMPT
RESULTS
NODAL THERM1
1
NODAL THERM2
LINE(S)
TOP_EDGE BOT_EDGE
THERMO
Step 9 |
Calculate the value of each integral.
RESULTS CALCULATE INTEGRATE LINE RESULTS CALCULATE INTEGRATE OFF; |
Step 10 |
Set an axis to have a log scale.
PRESENT OPTIONS GRAPH AXES YLOG |
Step 11 |
Finally you can specify the thickness of lines and no points.
PRESENT OPTIONS GRAPH LINES THICK; PRESENT OPTIONS GRAPH POINTS SYMBOLS OFF RESULTS RANGE EL-RESULT ALL
|
Figure 11.3: Graph of multiple results attribute on two lines