Crack Initiation and Growth Acoustic Emission Analysis with Finite Element Analysis for Structural Health Monitoring of Mooring Chains

Abstract

Mooring chains for floating off-shore installations, typically designed for a 25 year service life, are loaded in fatigue in a seawater environment. Moreover, the life of old structures has to be extended. This includes the replacement of expensive periodic in-service inspections with cost-efficient Structural Health Monitoring (SHM) with permanently installed sensors. Although successful at detecting and assessing the fatigue cracks, the hazardous nature of the operation calls for remote techniques that can be applied continuously to identify damage initiation and progress. Appropriate replacement plans must enhance current strategies by implementing real-time data retrofit. Acoustic Emission (AE) technique is capable of detecting cracks and fatigue dam in mooring chains. This paper describes a methodology of Finite Element Analysis (FEA) for crack initiation and crack growth simulation for Structural Health Monitoring (SHM) applying AE technology for damage detection.