Shuangxing Du
Ansys Employee

Please read Aqwa theory manual, 14.1 Effective Nodal Acceleration RAOs for the effective acceleration definition in Aqwa.  "accelerations+g" is not the effective accelerations from AQWA.

Please check your defnition of non-linear roll damping using the bilge keel properties, which may cause the linearization iteration failure.

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