Thickness data file-'.THK'

Cadfil Help contents      Cadfil.com Home

The Payout Path Generation section also generates thickness files. These are generated with a '.THK' extension. This file contains data relating to how the fibre file was generated,.

111 
REVIEW.MND 
244        2.377622        5.000000 
L1       X             R           ANG             T
1   .122600E+04   .612500E+02   .900000E+02   .952736E+01
2   .122562E+04   .624436E+02   .988438E+02   .952736E+01
3   .122538E+04   .632031E+02   .104283E+03   .952736E+01
4   .122445E+04   .660813E+02   .110899E+03   .783398E+01
5   .122328E+04   .697469E+02   .118565E+03   .553718E+01
6   .122241E+04   .724843E+02   .121806E+03   .483378E+01
7   .122000E+04   .800000E+02   .127532E+03   .378905E+01

The data contained within the file has the structure as outline below.

• Number of lines of data in file.
• Mandrel name used in fibre generation.
• NOCYCL, XSECAR, BANDW
• POINT, XCOORD, RADIUS, ANGLE, THICKNESS (COLUMN HEADER INFORMATION- L1 X R ANG T)
• NOCYCL No. of Cycles required for coverage. Free
• XSECAR Tow bundle cross section (mandrel units ²). Free
• BANDW Bandwidth used in Payout Path Generation. Free
• HEADER Column Header Information for data below.
• POINT Reference number of line in data file. I6
• XCOORD X co-ordinate of point ( Mandrel Units ) E13.6
• RADIUS Radius of mandrel at point. E13.6
• ANGLE Angle of fibre in degrees at X Co-ordinate E13.6
• THICKNESS Thickness of laminate at the X Co-ordinate. E13.6

If you considered the band of tow as a ribbon of uniform thickness this thickness would be XSECAR/BANDW. This thickness calculation is geometric and given by thickness =2*XSECAR*NOCYCL/(2.0*PI*BANDW/Cos(Angle))

Two things must be noted, firstly this is radial thickness not thickness normal to the surface. On a cylindrical part radial and normal thickness are the same on and end dome they are not the same they are related by the cosine of the mandrel slope angle at any point. The second point of note is that this method breaks down when the winding angle id close to 90 degrees as the thickness prediction tend to infinity. In this case an approximate method based on fibre length deposited over an area is used to approximate the thickness. A more detailed and accurate method is is to create the TH2 thickness file.

Thickness data file-'.TH2'

This is a thickness file calculated by a more rigorous but slower method. The representation of thickness in the turning zones is more accurate than the THK file. This file has a header record and 5 columns of data. These are:

• X The axial position on the mandrel in steps of 0.25 mandrel units (e.g. mm)  from one end of the mandrel to the other. You can also add the optional $THK2-XSTEP variable to the SM file to set the separation distance between to thickness points to whatever you want, e.g. $THK2-XSTEP=1.0, if you do not set this variable the default is 0.25.
• R the corresponding mandrel radius
• Angle, the corresponding winding angle in degrees
• t/t0 - Normalised  thickness normal to the mandrel surface. This is a multiple of the band thickness so if he value is 5 and the band thickness is 0.1 then the actual thickness is 0.5
• Slope - the corresponding mandrel slope angle in degrees.

After the table of date the minimum , maximum thicknesses and the max/min ratio are listed.

 X R Angle t/t0 Slope 
-182.75000 0.00000 0.00000 0.00000 0.00000 
-182.50000 8.00976 0.00000 0.00000 86.73756 
-182.25000 12.39558 0.00000 0.00000 86.73756
-182.00000 16.13464 0.00000 0.00000 84.56272
-181.75000 18.76113 0.00000 0.00000 84.56272
-181.50000 21.38761 0.00000 0.00000 84.56272
-181.25000 23.64350 0.00000 0.00000 82.38777
-181.00000 25.51411 0.00000 0.00000 82.38777
-180.75000 27.38473 0.00000 3.83375 82.38777
-180.50000 29.25535 0.00000 4.65482 82.38777
-180.25000 30.92886 0.00000 5.34312 80.21294
-180.00000 32.37816 0.00000 5.88293 80.21294
-179.75000 33.82745 0.00000 6.38004 80.21294
-179.50000 35.27675 0.00000 6.77866 80.21294
-179.00000 38.09292 79.59494 7.75170 78.03802
-178.75000 39.27293 72.37356 7.98568 78.03802
-178.50000 40.45293 67.85757 8.20831 78.03802
-178.25000 41.63294 64.21139 8.42018 78.03802
-178.00000 42.81295 60.97885 8.60871 78.03802
-177.75000 43.99296 58.41741 8.78464 78.03802
-177.50000 45.17063 56.02359 8.95298 75.86304
-177.25000 46.16321 54.17557 8.01150 75.86304
-177.00000 47.15579 52.66678 7.83686 75.86304
-176.75000 48.14838 51.15798 7.01614 75.86304
-176.50000 49.14096 49.64919 6.32632 75.86304
-176.25000 50.13354 48.27490 5.83715 75.86304
..... 
..... 
245.50000 29.04745 0.00000 4.50578 -72.69230
245.75000 28.24518 0.00000 4.00563 -72.69230
246.00000 27.44290 0.00000 3.48523 -72.69230
246.25000 26.64062 0.00000 2.79451 -72.69230
246.50000 25.83834 0.00000 1.95378 -72.69230
246.75000 25.03606 0.00000 0.00000 -72.69230
247.00000 24.23379 0.00000 0.00000 -72.69230
247.25000 23.08126 0.00000 0.00000 -79.61536
247.50000 21.71706 0.00000 0.00000 -79.61536
247.75000 20.35286 0.00000 0.00000 -79.61536
248.00000 18.98866 0.00000 0.00000 -79.61536
248.25000 17.62445 0.00000 0.00000 -79.61536
248.50000 16.26025 0.00000 0.00000 -79.61536
248.75000 14.89605 0.00000 0.00000 -79.61536
249.00000 13.53185 0.00000 0.00000 -79.61536
249.25000 12.16765 0.00000 0.00000 -79.61536
249.50000 8.26600 0.00000 0.00000 -86.53847
249.75000 4.13300 0.00000 0.00000 -86.53847 
250.00000 0.00000 0.00000 0.00000 -86.53847 
250.25000 0.00000 0.00000 0.00000 0.00000 
Minium Thickness= 0.204599544800921  
Maximum Thickness= 1.01503485418164   
Max/Min Ratio= 4.96108070606554 
 T0 (Ply Thickness)= 0.150000005960464
 MATL_NO=1