Mooring chain strength tests and ductile failure modeling using micromechanics and phenomenology based failure models

Abstract Mooring chains in many offshore floating facilities have failed due to overloading under extreme environmental events. The ductile failure in chains due to overloading has not been addressed in past studies. Therefore, the present study aims to analyze the ductile failure in chain links using micromechanics and phenomenology based numerical models. The material damage model parameters are established using material stress-strain plots obtained from tensile tests on coupons, extracted from a R3 grade steel chain link. The validation of material degradation models is achieved by comparing results from numerical studies and monotonic loading tests on mooring chain links of 76 mm nominal diameter. The material models successfully capture the failure mode and strength of the chain links.