FEATURE RECOGNITION AND STRENGTH ESTIMATION OF CHAIN LINKS USING 3D INSPECTION DATA FOR MOORING INTEGRITY ASSESSMENT

Abstract

Mooring systems restrict horizontal offset of floating vessels against a combination of loads arising from wind, waves and current. Past studies have observed extremely high failure probabilities which could be reduced through robust inspection and monitoring techniques. The current in-air inspection techniques are tedious, time consuming and expensive. And, the current in-water inspection techniques are unreliable and undergoing extensive research. The research work aimed at improving the in-water inspection technique by utilizing 3D inspection data of chain links for better mooring integrity assessment. The first part of the study focused on residual strength estimation of chain links by utilizing suitable material degradation model identified using ultimate strength tests on 76 mm stud chain links and material strength tests. The second part utilizes 3D scans and feature monitoring for weak link identification. The 3D point cloud data is further converted to FE models for residual strength estimation of degraded links.