GROUNDING DAMAGE ESTIMATE THROUGH ACCELERATION MEASUREMENTS

摘要

Instantaneous insight into the structural damage sustained by a ship running aground, can be of great aid in the decision making following such a disaster. It should be possible to distil the extent of structural damage from acceleration measurement data of the entire vessel. Such measurements could possibly even be done using a simple smartphone. This paper describes experimental research exploring the detection of plate rupture in a raking damage scenario by merely looking at acceleration measurement data. Drop tower experiments were performed, which reflect a realistic raking damage scenario and also aim to gain better understanding of both friction and failure in such a scenario. In total four drop tests were performed. Ductile fracture occurred without precedence of necking. A calibration method for a failure criterion, using only one single strain-state, was successfully applied. Separate friction tests showed that static Coulomb friction seems to be a proper model to be applied for the energy dissipation through friction. Moreover, the transition to plate rupture can readily be detected from the experimental acceleration data. When accurate calibration of both the failure and the friction is performed, it is envisaged that the extent of raking damage can indeed be derived through real time acceleration measurements on board of a vessel.