| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Saarimaki, Eetta
VTT Technical Research Centre of Finland
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (22/22 displayed)
- 2024Screening of suitable random copolymer polypropylene blends for HVDC cable insulationcitations
- 2023Molecular Layer Deposition of Polyurea on Silica Nanoparticles and Its Application in Dielectric Nanocompositescitations
- 2023Nano-scale nonwoven fabrics by electrospinning of polylactic acid
- 2021Dielectric performance of silica-filled nanocomposites based on miscible (PP/PP-HI) and immiscible (PP/EOC) polymer blendscitations
- 2021Dielectric Performance of Silica-Filled Nanocomposites Based on Miscible (PP/PP-HI) and Immiscible (PP/EOC) Polymer Blendscitations
- 2021Combining good dispersion with tailored charge trapping in nanodielectrics by hybrid functionalization of silicacitations
- 2021Deposition of Ureido and Methacrylate Functionalities onto Silica Nanoparticles and Its Effect on the Properties of Polypropylene-Based Nanodielectricscitations
- 2021PP/PP-HI/silica nanocomposites for HVDC cable insulationcitations
- 2020Silica surface modification with liquid rubbers & functional groups for new polyolefin-based dielectric nano-composites
- 2020Influence of polar and unpolar silica functionalization on the dielectric properties of PP/POE nanocompositescitations
- 2020Feasibility of Mini-Scale Injection Molding for Resource-Efficient Screening of PP-Based Cable Insulation Nanocompositescitations
- 2020Silica Functionalization: How Does it Affect Space Charge Accumulation in Nanodielectrics Under DC?
- 2020From Laboratory to Industrial Scalecitations
- 2019Silica-Polypropylene Nanocomposites for Film Capacitorscitations
- 2018Airborne Dust from Mechanically Recycled Cotton during Ring Spinning
- 2015Novel thermographic inspection method to detect the moisture in early stage of the water ingress and a procedure to remove the moisture from the composite structure
- 2013New high-quality mined nanomaterials mass produced for plastic and wood-plastic nanocomposites
- 2013PVC-wood composite
- 2009Development of thermographic inspection routine exploiting phase transition of water for moisture detection in aircraft structurescitations
- 2006Novel heat durable electromechanical filmcitations
- 2005Novel heat durable electromechanical filmscitations
- 2005Novel heat durable electromechanical film processingcitations
Places of action
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document
Novel thermographic inspection method to detect the moisture in early stage of the water ingress and a procedure to remove the moisture from the composite structure
Abstract
Penetrated water in the composite sandwich structures has caused problems in aircraft structures. Flight surfaces have been lost during the flights, because moisture corrodes the honeycomb and further reduces the strength of the adhesive. Water can also cause additional defects during the composite repairs, which have resulted because of the expansion of the moisture (in closed cavity), hence causing skin blow core phenomena during the curing cycle (heating) of the repair. The number of penetrated water-induced failures is rising, therefore penetrated water in the composite structures operating in arctic conditions has been a research activity in Finland for several years. VTT and Patria have worked recently in close co-operation to develop a method to detect moisture and remove it from the structure efficiently. Procedure is divided to three phases: 1. X-ray inspection, which can indicate suspected water in one or multiple honeycombs. 2. Drying procedure (several hours) 3. Thermographic inspection to verify remaining water. . X-ray inspection can detect assumed water ingress, if it fills most of one or several the honeycomb cells. The drawback is that there is no certainty, if the indication is from water or excess adhesive/resin from manufacturing process. If doubt of water ingress is observed during X-ray inspection, structure will go through special drying procedure. A gentle procedure to remove the water is applied to the honeycomb composite structure, because it is essential not to cause skin blow core effect during the drying phase. Honeycomb composite structure is heated under a low vacuum to vaporize moisture from the structure. Heating takes place several hours. Pulsed thermography is reported to indicate water ingress in the composite structure. However, water can t be distinguished from other liquids easily or at all by this method. Thermography was decided to be exploited by cooling the inspected structure under freezing conditions before inspection. Thermographic inspection based on the phase transition of water exploits the phase transition energy that is needed for the water ingress to be defrosted (melted). Water ingress indication is observed in specific phase transition temperature and insures the presence of water. An other advantage of this method is that no additional excitation source is needed for the tests. Method based on phase transition can be especially exploited during the long period of arctic weather conditions in Finland and other cold areas. Composite structures can be left outside in freezing conditions overnight and inspected when they have been brought in to warm conditions.