Cadfil Contains a database of Fibre and Resin Materials. For winding program calculation only two parameters are required, the width of the fibre band ( the band width) to determine the path spacing and and the band thickness to calculate the thickness of the winding if required.
The band width is a function of the fibre type and also of the dispensing system (payout head). The tension and guide system will affect if the fibre spreads into a wide type or if it bunches up like a rope. Based on the band width and the fibre and resin material properties this band thickness can be calculated. For this reason the user must add there own bandwidth data based on experience with the winding machine type.
The material database allows the user to :
a) Save fibre and resin material data for future use.
b) Set material data for a particular winding and report this information to the NC program file for traceability and to add operator instructions such as which resin to use and the number and type of rovings to use. A description of the material parameter post- processor logicals can be found in the section on Post-Processor Variables - @@LOGICAL@@.
c) Calculate band thickness.
d) Save Unidirectional composite properties (strength and stiffness) data for use in Cadfil stress calculation, a discussion of this in the hyperlink.
The material data is containing in and external file cadfil_material_data.csv found in the Cadfil system folder (C:\Cadfil\Cadfilxxx ). This is a comma separated value (CSV) file and can be opened and edited in Microsoft Excel or other spread sheet programs. The format and layout should not be changed but the user can add or remove entries as required. Note that as of CADFIL version 8.01 the material file is supplied in the Cadfil installation as both .CSV and .XLS formats.
By default Cadfil will now:
1] Look in the current working folder for cadfil_material_data.xls
2] Look in the Cadfil system folder (C:/Cadfil/Cadfilxxx) for cadfil_material_data.xls
If the file is not found or Cadfil detects that a valid version (currently 2003-2013) of excel is not installed it will then:
3] Look in the current working folder for cadfil_material_data.csv
4] Look in the Cadfil system folder (C:/Cadfil/Cadfilxxx) for cadfil_material_data.csv
Information in the Cadfil text window will inform file is being used.
The reasons for changing xls format is that it is much easier for a user to view and modify an excel file than a CSV text file and additionally there as some problems using csv files with the windows settings that are used by default in some countries. In some settings (,) is not the default separator in windows often (;) is used but other separators are possible, the main reason is that (,) is sometimes used as a decimal separator in numbers. The problem is that when you open a CSV file in excel it assumes the default windows separator and if this is not comma (,) it corrupts the Cadfil material data on reading. As a fix for this we added the text "SEP=," to line one of the CSV file which forces excel to always read it correctly. However if you then save as type .csv excel will use the default separator which if this is not(,) it will create a file that Cadfil cannot read correctly. We have retained the csv functionality such that excel is not a pre-requisite of using this feature in Cadfil. While most users will have excel installed some will not. There is a workaround in that if you go into the windows control panel and into the language and regional settings (the names has some variation dependant on windows version) you can find and option to set the default separator and can change this to comma. Please note however that this may then effect other programs in ways of which we have no knowledge.
Please also note we are using XLS files NOT the newer XLSX style as this is then compatible with a wider range of Excel versions.
An example of such a CSV/XLS file viewed in Excel is show below.
The first two lines are header information and show the units and item description. Currently only the tex , density and bandwidth values are used for calculation the other information is there for reference and for future use.
Category currently must be "Fibre" or "Resin".
Type is "Carbon", "Glass" , "Aramid" or "Other" for Fibres and "Epoxy", "Polyester" or "Other" for Resins.
The other parameters are standard material parameters that can be found in manufacturers technical data-sheet.
The user can set material data from the Cadfil Main option menu or from the 'Material Properties' button that occurs on various dialogues during program generation. When the set materials options is selected the dialog shown below is displayed.
The Roving type can be changed from the pull down menu. The Roving description pull down will show all the rovings of the current roving type that are in the database. A roving material can be selected by clicking on it from the pull down menu. The same logic applies to resin type and resin description. The current selections are the ones shown in the dialog and the properties are the current properties that apply to this selection. The material data is fixed in the database the only one that the user can override /change on this screen is the roving width (band-width).
On selecting OK the following screen is shown.
This displays the current selection of materials and the user can set the number of rovings being used for the current winding. It is also possible to set the expect finre volume fraction or fibre mass fraction for the final composite that is expected. The calculate button shown the current band width (roving width x Number of rovings) and the expected can thickness given the specified material properties and fibre fraction. The 'calculate' is also automatically performed when the screen is exited with the OK option.
Band Width and Band thickness are the only parameters required to calculate a winding program.