Creep and shrinkage for quad elements

SOFiSTiK
2

Hello

The effect of creep and shrinkage can be obtained from a QUAD-system. You have to look at the 4XXX or 5XXX load cases. I will do the calculation using the following TEDDY example.

TEDDY > File > Examples > csm > english > csm4_quad_singlespan.dat

  1. Open the Graphic (Wingraf) and visualise the tendon stresses (or forces)
    grafik
  2. The difference between the 4XXX load cases describe the losses due to relaxation, creep and shrinkage. For example:
    (1) load case 4011: 1279,73 MPa (on the rigth side of the singlespan)
    (2) load case 4027: 1147,98 MPa
    (3) Difference: 131,75 MPa
    The same result can be obtained by adding the load cases 5020+5025+5026+5027=131,75 MPa
  3. Now you know the loses due to k+s+r. If you want the loses due to kreep+shrinkage you need to subtract the relaxation proption.
    (1) total tendon relaxation in load case 4027: 4% → 0,04 * 1279,73 = 51,79 MPa
    (2) kreep+shrinkage: 131,75-51,79=79,96 MPa

I hope that with this example you understand how to calculate the stress losses within a tendon.

Best regards
Frederik Höller
Your SOFiSTiK Support Team

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