MECOS#1

Elbow calculations

 

What is the temperature during the test ?

No temperature record was performed during the test. Given the Indian weather in February, the air temperature is assumed to be equal to 25°C.

 

The yield and ultimate stress values for SS304LN do not match between the "MECOS benchmark MECOS#1 data for elbow computation " document and the "Fatigue Ratcheting Investigation on Pressurised Elbows made of SS304LN" article. Should it be assumed that the correct values are those in the article?  

The correct values are those in "MECOS benchmark MECOS#1 data for elbow computation "

 

The ratcheting strain evolution is asked to be computed for 150 cycles. However, in the given excel sheet, data is given only up to 30 cycles. Is this a typo mistake?

No, some gauges failed during the test; hence the data may be limited. 

 

What is the original ovalization of the elbow ?

We do not have any information regarding the original ovalization of the elbow. Yet, thanks to the curve loading VS displacement, the orginal stiffness can be computed. 

 

At the beginning of the test procedure, more precisely when the internal pressure is implemented with the elbow, was the vertical displacement of the top swivel joint allowed ?

Yes. The vertical displacement of the top swivel joint has been allowed during the internal pressurisation. Later, cyclic load line displacement has been applied using actuator. Hence, z=0 corresponds to a state with internal pressure.

 

Within the header of the first column is noted that “Deformation in 10-6”. Is this value a multiplication factor to be applied to the strain values posted for G1, G2, etc ?

Yes, within this result file, the strain value has to be express in micro strain.

For instance, say that your FEA analysis gives you a deformation equal to 6 10-5 m/m , you will write 60 within the result files.