Fatigue analysis - 30 Years design life

Hi Richard,

I am new to fatigue analysis using Caesar-II. One of my contract scope is to design the piping system (B31.3) for a life of 35 years. Since it exceeds the 7000 cycle, so i must consider the fatigue analysis (i.e.)365*35 = 12775 cycles which corresponds to a stress range factor of 0.905. So to consider this effect in the allowable stress range, in Caesar-II where is the provision to enter the stress range factor. If not, am i have to do the fatigue analysis, if so where can i find the stress range factor - figure 302.3.5 in Caesar-II or the fatigue material curve.

Please clarify....

Fn

B31.3 - the stress range reduction factor is obtained from equation (1c), corresponding to Fig 302.3.5. Note that if certain criteria are met, the stress range reduction factor is allowed to exceed 1.0. Note also that for B31.3, the number of cycles can be specified in this field, which allows CAESAR II to compute the cyclic reduction factor according to equation (1c).

You can also specify the number of load cycles on a "per load case" basis, in the Static Load Case Editor. Then c2 will determine "f" for each load case.

Thankyou very much Mr.Dan and Mr.Richard.