| 1. |
- Andersson, Sara, et al.
(författare)
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Damage monitoring of ship FRP during exposure to explosion impacts
- 2011
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Konferensbidrag (refereegranskat)abstract
- Fiber Reinforced Plastics (FRP) has been used by Kockums' shipyard in the manufacturing of ships over 35 years, during which time is has been proven to be durable and practical. The light weight makes it a more and more attractive material as energy and material expenditure decreases are required. A special application is the Composite Superstructure Concept [1] where composite materials are added on top of a steel hull, which decreases the weight and running costs considerably, and makes it possible to even add extra levels while keeping the same center of gravity. If efficient condition monitoring systems can keep track of emerging damages of the structure, the weight may be even more reduced and the interval between maintenance inspections may be prolonged. As important steps in this process, a ship mock-up section was subjected to increased levels of explosive underwater impacts, and the damage progression in the hull was monitored by a nonlinear acoustic technique.
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| 2. |
- Hedberg, Claes, et al.
(författare)
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Ultrasonic monitoring of a fiber reinforced plastic : steel composite beam during fatigue
- 2012
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Ingår i: Proceedings of the 6th European Workshop - Structural Health Monitoring 2012, EWSHM 2012. - Dresden : German Society for Nondestructive Testing. ; , s. 1254-1260
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Konferensbidrag (refereegranskat)abstract
- The use of composite superstructures on current or newly built steel hulls is a recently emerged technology. The economic estimations predict that the extra costs for putting composite superstructures, with the present safety margins, on steel ships will be paid back in only 2-3 years. This also makes the ships having smaller ecological footprints with less fuel consumption and CO2 emissions. In this stage of development it is needed to ensure the durability of the joints between the steel and glass fiber reinforced plastic. The first step is that the joints must first be proven to withstand fatigue. In this test a 4-meter beam, which represents the joint, were investigated for fatigue progression by a four-point-bending fatigue test. In order to show that ultrasonic material monitoring techniques can be used to monitor the damage progression, the beam was measured during the tests until failure. The test was successful both in showing that the joint could withstand high levels of mechanical exposure, and in that the ultrasonic techniques accompanied the damage progression which means that they may be used on vessels during operation
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