How do I input “General – User Defined” circular tendons for tank structures?
Refer to Section 6.2.3 (see 6.1.3 for US units) of the FELT Users Manual for the example below.  See Curved Tendon (rename with .flt extension). Since both the tendons are covering half of the tank as shown on Page 6-24, it would cover a length of:

L = Half Perimeter + 2 * Stressing Ends Length

= {(22/7) * 23.16} + (2* 1524) = 72.79 + 3.05 = 75.84 m

Hence total angle change per meter should be = 180 / 75.84 = 2.37 degree

Fir the input we have 3m on both straight ends. It is assumed Span 1 and 3 are straight, while Span 2 is curved. So Span 2 = 69.84 m

To make the curvature smooth we divide into 9 divisions, each division =

69.84 /9 = 7.76 m, during input a round up value of 7.75 m is shown.

Change of angle for this length would be = 2.37 * 7.76 = 18.39 degree. During input a value of 18.4 is used.

To obtain the input pattern as specified, inside Geometry dialog make shape 4 for all three spans. Then under selection select “User Defined”.

You will notice the choice of input will appear as “Coordinate Entry”, “Length/ Angle Entry” or “X, Y, Z Entry”. You may select Length/Angle option to enter the values as specified.

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