During the analysis it is always possible to activate the graph window from the Analysis windows menu item Show graph.
This can help giving a quick graphical overview of test data and results.
The window can be switched off again by clicking Hide graph from the menu.
If the window is activated during calculations, it will show constantly the results generated during the iterations. This will slow down the calculation time.
When structural information and seed values have been entered in the Analysis window (see: Structure and Seed Values), then the calculation of layer properties can be started. Below is an example of input information:
The last 5 drops from a series of 18 have been selected for the analysis (see: File Settings). This means the analysis will try to create the results that will make the best fit with the test results for these 5 drops. Single drops can be omitted by clicking in the grid in the Use column.
A 2-layer system has been entered, and some seed values inserted. The seed values are start values for the iteration procedures, and should be selected as realistic as possible.
Start the analysis for the selected point by clicking Calculate point. When finished the results are seen from the grid and from the Result frame:
T he results inserted in the grid are now reflecting the calculated values in the Result frame, rather than the input values from the Structure frame as described in Structure and Seed Values when clicking the Deflections button. Follow this link to get information about the columns in the grid.
In the Result frame you see the calculated values for each layer. These results reflect the values found from the back-calculation iterations, that fit best (minimize RMS) to all drops included in the analysis. It is only an advantage if the drops included are done with various load levels and plate sizes. The overall RMS is listed below the grid, and the overall Eo, surface deflection modulus is listed in the Surface Modulus Design frame.
When calculating only for the single point, then no results are saved before you press the Save button, next to the Calculate point button.
This allows doing experiments and consequence analysis for a single point before saving and before running all points.
When you click the Calculate Project button, then all points will be calculated and all results saved automatically.
At any time you can go back to a single point and do single point analysis, and save new results for that specific point.
New values as seeds can be clicked to transfer the results to seed values for preparing another analysis. This can in some cases improve the results.
Width, Steps andAlternate are input to the iteration procedures. The higher values for width and steps the more wide and detailed iteration, which in some cases can improve the RMS value, but will also increase the calculation time. Alternate indicates shifts between iteration based on minimizing the percentual difference and the absolute difference between measured and calculated deflections. The default is to alternate 2 times based on the checkbox input next to the RMS value which makes the iteration run consecutively, shifting between absolute and percentual, the number of times indicated. Higher values will increase the calculation time, but can in some cases improve the RMS value. The fastest calculation will be for the minimum allowable values, which are Width = 1, Steps = 1 and Alternate = 0.
To continue with design calculation, see Calculation of Required Overlay Thickness.
8.7Calculation of Required Overlay Thickness
When analysis of layer properties has been done for a point (see Calculation of Elastic Moduli), then a design overlay thickness can be calculated.
The design overlay thickness is calculated as the thickness of an overlay material with a given elastic modulus, which will result in a design surface modulus.
The modulus of the overlay material is set in File Settings, where standard plate radius and stress level is also entered.
From the analysis of layer properties the field Existing surface modulus is filled in, and you will then have to enter the Required surface modulus.
When clicking Calculate point, the required overlay thickness is calculated and shown in Required thickness field.
You can then click Save to save the results only for this point, or click Calculate project to calculate and automatically save results for all points in the file.
Please notice that you must not enter a required surface modulus that is higher than the modulus of the design material.
Selecting Report from the Main menu gives possibilities to have test data and analysis results listed in tables, and following export them to Excel or Word for further processing or printing.
At the top of the window you have options for which columns you want to include in the report. As default is included what was used previously.
Either Point No. or Location must be included. Click the Create button to generate the tables with data. If no analysis results are present this table will be left empty.
You can now create the export by clicking Send to Excel or Send to Word. Export to Excel will automatically load the Excel application and create a sheet with test results and a sheet with analysis results. The Excel file is not saved automatically. If you want to save it, you must do it manually from the Excel menu.
Export to Word will automatically load a Word document and create pages with test results and analysis results. The Word document is not saved automatically. If you want to save it, you must do it manually from the Word menu.