The strip theory method has been expanded with additional roll damping

The strip theory method of PIAS’ Motions has been expanded with the option to include additional roll damping. The implementation is based on el Moctar, B. O., Schellin, T. E., & Söding, H. (2021). Numerical Methods for Seakeeping Problems, Springer International Publishing. Strip theory is based on the potential theory, which does not account for frictional resistance, which may cause the damping to be underestimated, notably for the roll motion. By including additional roll damping through the input of a damping ratio, the roll motions can be estimated more accurately.

The damping ratio is a physical quantity, which can be measured through a free roll decay or forced roll test.