This menu controls the generation of fibre tracks on the mandrel surface. Through out path generation the current path X position (X), mandrel radius (R), winding angle (A), point number (N) and friction status are displayed in the text window.
The options are as below:
Exit This returns control to the main menu. The user is asked if he wishes to save the fibre path data before exiting. Having saved the fibre the option to proceed to creating the payout path is given.
Action This option creates a number of fibre path segments (a segment crosses one mandrel patch). This defaults to 1 segment but can be set with the STEP option. The path created will be geodesic unless the friction option has been set at which point it will be a friction modified geodesic.
Set Step This sets the number of fibre segments to create at every selection of ACTION. The use is asked ENTER FIBRE CREATION STEP. After entering a number ACTION is then assumed.
Delete This option deletes a number of fibre segments. The user is asked ENTER NUMBER TO DELETE. This number of segments is deleted from the end of the fibre path. If the number of segments exceeds the current number of points that exist the path is deleted back to point number 2. Zero can be entered to abort. The use of DELETE and STEP permits the user to delete and regenerate the last part of the path changing the friction value in between, until the optimum path is achieved.
View Options This enables the CADFIL views menu to be accessed. This allows the view angle to be changed, output of graphics and other facilities such as ZOOM and PAN. This is described in a later section of this manual.
Display Options, these option permit the user to select how he would like to display the fibre path. These options take effect when redraw is selected. The options are as follows:
Rotate Axis The ROT X option enables the user to rotate the fibre path around the component, the X axis being the component's axis of revolution. This path rotation is carried out in the current view. Whenever a new view is selected, any relative X rotation entered using this command is lost, as the display is mandrel and fibre are drawn in the selected view orientation. The system prompts: Enter relative x-axis rotation a value in degrees should be entered. The fibre path will then be redrawn, the original path remaining visible. The value entered here is the motion to move the fibre track from where it is now, to its new position.
DRAW This clears the screen and draws the fibre and mandrel mesh in the currently selected view with the current HIDDEN option.
Friction LH Sets Left Hand friction. The direction of friction is when looking onto the surface of the mandrel facing in the direction in which the path is being created, thus LH friction deviates to the left and RH friction to the right. When friction is selected the user is requested to enter the friction percentage a value from 0-100 which can be entered in steps of 0.1 e.g. 33.1%. This is the proportion on the friction coefficient, a value defined in the MATERIAL.CNF data file. This can be modified if required. The higher the friction value the more rapid the change in fibre direction. If the MATERIAL.CNF file is not found a default of μ=0.124 is used.
The user will be able to maximise the benefit achievable by using frictionally sustained paths, if for each fibre/resin system used, the maximum coefficient of friction attainable is first determined. For example, pre-impregnated carbon/epoxy tape will have a significantly higher friction coefficient when compared to a system of polyester resin wetting out glass fibres pulled through a resin bath.
Geodesic. This option sets zero friction i.e. the path will continue geodesically.
Friction RHsets Right Hand friction. See Friction LH.
Const Angle. This option forces the fibre path to continue at a constant angle, this angle being the current angle. This option cannot be set on the first point of a fibre path. This option is useful for winding along mildly tapering cylinders where it would be difficult to keep progressively changing friction to maintain a wind angle. Warning: at present this option does not check the level of friction that is required to maintain the constant angle and hence if this option is used in an inappropriate manner the fibre path may not be feasible to wind due to slippage. Friction checking will be available in a later version of CADFIL.
PATRAN Output. This option allows model data to be output as a PATRAN neutral file containing shell elements. The user is asked for the name of the file to create. The extension '.ptn' is added to the file name entered.
Test Hoop Points. This prints a summary (to the text window) of the X-position and radial opening for each hoop point in the winding file and is useful to determine if there are two acceptable hoop points for create a payout path or to determine the size of the end openings that have been generated.