hi guys my H/D ratio is 1.6 can any one suggest me what will be the value of Ci. since in APi 650 value of Ci is available only for H/D ration from 0 to 1.5.
Extrapolating from the graph would probably be as good as anything.
The graph is based on the Veletsos method with some modifications, and you could work that out in detail if desired. There is still a certain amount of approximation built in.