Reply To: Connection Stiffness Ansys AQWA

[S.S.S.ShankaVasuki]

 

 

Thank you for your response,

                 I did try to run the simulation as per your suggestion and I do have some questions.

1. I am focusing on running the simulation for a Regular wave of amplitude 1m and frequency 0.7rad/s . But this analysis requires an irregular wave as an input. So I am wondering does this method give me the results I am looking for because the spectrum defines the results and the surface elevation would different for an irregular wave which would change the values of the RAOs?
2. Also, I did use the JONSWAP spectrum as a trial case, and entered the starting and ending frequency manually as 0.71513 and 1rad/s, the significant wave height as 0.5m, gamma as 1 and the peak frequency as 0.8rad/s , and I did calculate the heave RAO for all the 4 bodies and these are the values,

 

 

         Part 1 : 0.239 m/m

         Part 2 : 0.12 m/m

         Part 3 : 0.0162 m/m

         Part 4 : 0.10151 m/m

But according to the paper I am trying to validate, the results are not what I am looking for. I have attached the validation plot to this thread for your reference. 

3. Another weird thing I observed is that I get the same results when I have no stiffness mentioned for the hinge joint and when I specify a value of 6270000000 Nm/rad. I am not able to understand this as the results should change based on the stiffness I provide right? Maybe I am doing something wrong.

Please let me know where I could have gone wrong. 

Thanks