This work derives a forcing function that is intended for performance evaluation of a marine fender. The forcing function is based on the physics of a realistic berthing scenario and is presented in terms of force, deflection, and time. Presenting the forcing function in these terms will facilitate implementation using modern-day actuators and control systems. The forcing function is compared with the guidelines of the current ASTM standard, ASTM F2192-05(2017), Standard Test Method for Determining and Reporting the Berthing Energy and Reaction of Marine Fenders, for testing and reporting the performance of marine fenders, as well as the World Association for Waterborne Transport Infrastructure (PIANC) guidelines. It was found that the velocity regime for an actual berthing scenario is nonlinear, while the ASTM standard and PIANC guidelines provide for both linear and nonlinear decreasing velocity regimes when testing, none of which conform to the berthing scenario. It was also found that the duration of a test, using the current standard, is longer than the duration of an actual berthing scenario. In addition, it was determined that the energy-based approach provided in the current ASTM standard is identical to the physics of a berthing scenario. However, a shortcoming of the energy-based approach, as presented, is the difficulty in implementation, because the equation provided in the standard is in terms of energy, which is not programmable into controllers of testing equipment. The methodology presented here will yield input values for testing that are a realistic description of a vessel coming to rest at berth. This approach may be used for a unique vessel of particular significance, a specific class of vessels, or in general performance testing. It is expected that the results presented here are a basis for test parameters that will be an accurate description of field conditions.
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