Over the last few years the large yacht industry has been gradually adjusting to life in a modern, regulatory environment. One area that lacks quantitative inspection methods however, is the examination of masts and spars, and in particular how initial and through life performance is assessed for fibre reinforced structures. When does a carbon mast need repair, or replacement? How does a manufacturing defect, or damage during installation or service affect its integrity, and is it still serviceable and safe?

The UK Department of Trade and Industry (DTI) and an industry consortium formed a collaborative research project to investigate the effect of defects in composite masts and spars and to provide methodologies for the design and manufacture of damage tolerant structures.

The project, entitled MSI Spar, was designed to investigate the damage tolerance of composite large yacht spars, with the aim to deliver improvements in structural durability, design and quality control. This included the use of modelling, mechanical testing and Structural Health Monitoring (SHM) as well as the development and application of non-destructive technologies for structural polymer-matrix composites. Demand for CFRPs is growing rapidly in new generations of long, highly loaded components such as high performance yacht spars. This industry does not apply state of the art inspection and damage tolerance approaches such as developed for the aerospace industry. Requirements for SHM are increasing but need to be integrated with non-destructive and destructive test methods. This project developed novel RapidScan ultrasonic equipment and effect-of-defects testing methodologies integrated with SHM methods. The results have been delivered as non-destructive testing hardware, and importantly, life assessment methodologies encompassed in documented guidance.