Self-Healing of Wind Turbine Blades Using Microscale Vascular Vessels

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Arun Kumar Koralagundi Matt ◽  
Saman Beyhaghi ◽  
Ryoichi S. Amano ◽  
Jie Guo

Development of high bending stresses due to a sudden gust of wind is a significant cause for the failure of wind turbine blades. Self-healing provides a fool proof safety measure against catastrophic failure by healing the damages autonomously, as they originate. In this study, biomimetic, vascular channel type of self-healing was implemented in glass fiber reinforced polymer matrix composite that is used in wind turbine blades. Microscale borosilicate tubes are used to supply the healing agent to the epoxy type of thermoset polymer matrix, and the healing was very effective. However, 25% decrease in tensile strength and 9% decrease in three-point bending flexural strength were imminent with the inclusion of a single layer of vascular vessels in the composite material. Three-point bending tests were performed before and after self-healing of flat specimens to find the extent of recovery of flexural strength on using vascular channel type of self-healing. An average recovery of flexural strength of 84.52% was obtained using a single layer of vascular vessels on the tensile stress side of three-point bending. Breakage and bleeding of the healing agent within the composite specimens during three-point bending tests were observed in real-time. Based on the encouraging findings, the above self-healing feature was successfully implemented in a prototype wind turbine.

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Rulin Shen ◽  
Ryoichi S. Amano ◽  
Giovanni Lewinski ◽  
Arun Kumar Koralagundi Matt

Self-healing wind turbine blades offer a substantial offset for costly blade repairs and failures. We discuss the efforts made to optimize the self-healing properties of wind turbine blades and provide a new system to maximize this offset. Copper wire coated by paraffin wax was embedded into fiber-reinforced polymer (FRP) samples incorporated with Grubbs' first-generation catalyst. The wires were extracted from cured samples to create cavities that were then injected with the healing agent, dicyclopentadiene (DCPD). Upon sample failure, the DCPD and catalyst react to form a thermosetting polymer to heal any crack propagation. Three-point bending flexural tests were performed to obtain the maximum flexural strengths of the FRP samples before and after recovery. Using those results, a hierarchy of various vascular network configurations was derived. To evaluate the healing system's effect in a real-life application, a prototype wind turbine was fabricated and wind tunnel testing was conducted. Using ultraviolet (UV) dye, storage and transport processes of the healing agent were observed. After 24 h of curing time, Raman spectroscopy was performed. The UV dye showed dispersion into the failure zone, and the Raman spectra showed the DCPD was polymerized to polydicyclopentadiene (PDCPD). Both the flexural and wind tunnel test samples were able to heal successfully, proving the validity of the process.


2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Rulin Shen ◽  
Meijian Ren ◽  
Ryoichi S. Amano ◽  
Mingjun Long ◽  
Yanling Gong

Abstract Self-healing is a promising way to solve the difficulty in wind turbine blades repair, yet the embedded healing agent may have a disadvantage because of being exposed to outdoor for a long time. Pressurized delivery of the healing agent in real-time when the blade is damaged may be the solution to avoid the disadvantage healing agent. In this paper, the healing agent was pumped to the damaged area by a peristaltic pump, and the healing effect was evaluated by the recovery rate of the residual flexural strength after impact and the image of ultrasonic C-scan. To evaluate the healing effect of different damage degrees, 10 J, 15 J, 20 J, and 25 J impact energies were applied. The fluid tracer test showed that the healing agent could penetrate in the damaged areas after the impact of 15 J, 20 J and 25 J, while the three-point bending test revealed that the healing efficiency was the highest with 20 J (85.2%). The ultrasonic C-scan and optical photos of the sample showed that the images of the healing area were almost consistent with those of the un-impacted area, indicating that the damaged area is healed well. Based on the success of plate samples, the self-healing of the wind turbine blade-scale prototype was then carried out. Twenty-joule impact was exerted on the blade prototype, and the healing agent was pumped to the damaged area using the peristaltic pump similar to the same procedure as that of the plate specimen. Ultrasonic C-scan and optical images of the damaged area showed that the prototype was healed well in comparison with those of the plate specimens, indicating that the application of pressurized delivery of the healing agent system in the self-healing of wind turbine blade prototype was successful.


2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Arun Kumar Koralagundi Matt ◽  
Shawn Strong ◽  
Tarek ElGammal ◽  
Ryoichi S. Amano

Wind turbine blades undergo fatigue and their performance depletes as time progresses due to the formation of internal cracks. Self-healing in polymers is a unique characteristic used to heal the cracks inherently as they form. In this study, a new method is demonstrated for supplying the monomer (that is quintessential for the healing process) uniformly throughout a fiber reinforced polymer composite. Commercial tubes were used to produce a vascular network for increased accessibility of the healing agent. The tube layouts were varied and their effect on the composite structure was observed. Conventional glass fiber reinforced polymer matrix composites (PMC) without microtubing were tested using dynamic mechanical analysis (DMA) to study the flexural visco–elastic behavior. The vascular network arrangement coupled with DMA data can be used to uniformly supply appropriate amount of healing agent to implement Self-healing in fiber reinforced PMC.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Rulin Shen ◽  
Ryoichi S. Amano ◽  
Giovanni Lewinski

Hollows produced by wires and borosilicate tubes are two significant approaches for the storage and transport of healing agent for self-healing wind turbine blades. To compare the performance for the two approaches, sheet samples and prototype blades were molded with vacuum-assisted resin transfer molding (VARTM) and max-flexural strength was evaluated before and after the self-healing process. One millimeter outer diameter with 0.5 mm inner diameter borosilicate tubes were used to store and transport the healing agent. Dicyclopentadiene was used as the healing agent and Grubbs' first-generation catalyst was used to initiate polymerization. To obtain the same structure of the tube, a lost-wax method was applied twice to form hollows with 1 mm outer diameter and 0.5 mm inner diameter. Since the samples need to be heated to form the hollows, the effect of the heating process on flexural strength was investigated. The flexural strength of the samples showed to be enhanced with the heating process. The percentage improval for flexural strength was 14.18% at 120 °C, 21.79% at 135 °C, and 10.89% at 150 °C. The growth trend continued until 135 °C and decreased after 135 °C. The toughness of the samples was also weakened. With the heating process, the initial and post self-healing flexural strength between samples with tubes and samples with hollows showed little difference. The recovery percentage of samples with tubes was 81.55%, while that of samples with hollows was 81.92%. Without the heating process, the initial and post self-healing flexural strength between samples with tubes and samples with hollows also showed little difference. The recovery percentage of samples with tubes was 89.52%, while that of samples with hollows was 89.46%. The space between the tubes/hollows greatly affected the flexural strength. The flexural strength of samples with a larger space between tubes/hollows was higher than that of samples with a smaller space between tubes/samples. For the prototype wind turbine blade, the initial and post self-healing flexural strength followed the same trend. For samples with hollows, the ratio of the inner diameter to outer diameter can be close to one so the walls can be very thin improving storage and transport efficiency.


2009 ◽  
Vol 129 (5) ◽  
pp. 689-695
Author(s):  
Masayuki Minowa ◽  
Shinichi Sumi ◽  
Masayasu Minami ◽  
Kenji Horii

2021 ◽  
Author(s):  
Aileen G. Bowen Perez ◽  
Giovanni Zucco ◽  
Paul Weaver

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