Ultrasonic Testing (UT) of Composite Boats and Spars:
Many modern boats are built from composites – a combination of fibers and plastic matrices. Fibers might be randomly arranged, then flattened
into a sheet (called a chopped strand mat), or woven into a fabric. The fiber material is often glass, aramid or carbon where the plastic matrix is most often based on polymers such as polyester, vinylester or epoxy resins.
Moreover, the trend for carbon fiber spars for sailboats is on the rise. Nowadays, carbon fiber spars are not only seen on racers but are also placed on a range of vessels such as cruising yachts, mega yachts and even on classic yachts.
Due to the prevalence of fiber-reinforced composites (whether it is glass, aramid or carbon fibers) in boats, and due to lower safety coefficients, the need for damage-detection and characterization has increased.
Hidden internal flaws and defects within a composite structure are not uncommon. These hidden flaws and defects might be resulting from manufacturing anomalies, applied stresses or weaknesses, accidents or improper repairs. They can have a significant impact on the structural integrity of the boat and are normally not detectable by radiography or by NDT techniques other than Ultrasonic Testing (UT).
Ultrasonic Testing (UT) can be used to detect the following:
- Uniformity of laminate thickness
- Presence and type of delaminations
- Presence of voids and/or porosity
- Quality and bonding of laminate and integrity of repairs
- Inclusions and alien material presence in laminate
Advantages of Ultrasonic Testing of Composite Boats and Spars:
- One-sided access is sufficient
- Highly portable equipment provides inspections at remote locations and – at a pinch – even working aloft
- Minimal or no surface preparation is needed
- Highly accurate in determining the exact point of a hidden anomaly and its main characteristics such as depth, size and shape
- Provides instantaneous results and objective data
Ultrasonic testing with the correct equipment and standard samples and with well-trained operators is a powerful and non-invasive method of detecting flaws and defects in composite materials. marineSOLUTIONS has invested extensively in the training of personnel, assortment of equipment and standard samples. Equipment and standard samples can be applied to many composite requirements.
We use Olympus Epoch 650 Ultrasonic Flaw Detector, a state of the art digital flaw detector and Olympus Panametrics transducers some of which are specially designed and developed for inspection of composites. The instrument configuration is accepted and used in aerospace industry. The instrument calibration is kept up to date.