Mosciatti Urzua et al 2025a - Revision history

Marherna: Marherna moved page Review 737018348742 to Mosciatti Urzua et al 2025a

2025-07-23T11:40:55Z

Marherna moved page Review 737018348742 to Mosciatti Urzua et al 2025a

Eziomosciatti: Fixed translation error: Energy matrix => energy mix

2025-07-07T10:21:03Z

Fixed translation error: Energy matrix => energy mix

Eziomosciatti: Updated figures 1, 5 and 3 to improve readability and homogenize format. Also, changed the name of section 4.4, since it was the same as that of section 4.

2025-07-07T10:10:09Z

Updated figures 1, 5 and 3 to improve readability and homogenize format. Also, changed the name of section 4.4, since it was the same as that of section 4.

Eziomosciatti: Sections numbering

2025-07-04T12:37:31Z

Sections numbering

Eziomosciatti: Table 1 link

2025-07-04T12:32:08Z

Table 1 link

Eziomosciatti: Implementation of the simplest of reviewer B's observations

2025-07-04T12:07:44Z

Implementation of the simplest of reviewer B's observations

Marherna at 08:26, 30 June 2025

2025-06-30T08:26:03Z

Marherna at 08:25, 30 June 2025

2025-06-30T08:25:43Z

Eziomosciatti: Eziomosciatti moved page Draft Mosciatti Urzua 152521725 to Review 737018348742

2025-04-30T17:03:38Z

Eziomosciatti moved page Draft Mosciatti Urzua 152521725 to Review 737018348742

Eziomosciatti at 16:57, 30 April 2025

2025-04-30T16:57:41Z

@@ Line 4: / Line 4: @@
 ==1. Introduction==
-It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.
+It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy mix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.
 ==2. Materials selection==

@@ Line 22: / Line 22: @@
 The kinetic study was later complemented by comparing cured and postcured unreinforced samples, with the objective of comparing their glass transition temperature (Tg). A differential scanning calorimetry (DSC) was carried out for both cases. The resulting calorimetry curves are shown in <span id='cite-_Ref196411681'></span>[[#_Ref196411681|Figure 1]].
-The red curve corresponds to samples that underwent 24 hours of ambient temperature curing. The samples from the black curve were cured in the same fashion, and then postcured for 3 hours at 80ºC
+The red curve corresponds to samples that underwent 24 hours of ambient temperature curing. The samples from the black curve were cured in the same fashion, and then postcured for 3 hours at 80ºC.
+[[File:Calorimetry 1 re.png|centre|thumb|703x703px]]
-<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
- [[Image:Draft_Mosciatti Urzua_152521725-image1-c.png|600px]] </div>
-−
 <div id="_Ref196411681" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 ''Figure 1: Cured and postcured samples' calorimetry curves.''</div>
@@ Line 100: / Line 97: @@
 After ageing, the samples were subjected to a controlled drying process under vacuum at 45°C to assess any potential weight loss, which would indicate leaching by hydrolysis – a sign of chemical degradation induced by the aqueous environment. As also shown in the desorption curve of <span id='cite-_Ref195020510'></span>[[#_Ref195020510|Figure 3]],''' '''no such weight loss was detected, and the samples regained their original mass. The presence of physical (reversible) ageing was further validated by thermal analysis experiments, detailed in the <span id='cite-_Ref196826931'></span>[[#_Ref196826931|Thermal Analysis vs Ageing]]'' ''section.
+[[File:Absorption desorption re.png|centre|thumb|589x589px]]
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-[[File:Draft_Mosciatti_Urzua_152521725_2565_Water uptake curve of transverse tensile samples after 24 h and desorption curve.png|450px]] </div>
+''Figure 3: Water uptake curve of tensile (transverse) samples after 24 h and desorption curve.'' </div><span id="_Ref196826686"></span>
-<div id="_Ref195020510" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 ''Figure 3: Water uptake curve of tensile (transverse) samples after 24 h and desorption curve.''</div>
-−
-<span id='_Ref196826686'></span>
 ===4.2. Void Content Study===
@@ Line 126: / Line 119: @@
 ===4.3. Thermal Recovery Post-Ageing===
-A further DSC test was carried out to compare samples in their virgin state, and during and after ageing, as well as after redrying. <span id='cite-_Ref195082609'></span>[[#_Ref195082609|Figure 5]] shows that material properties are recovered after drying, indicating that the ageing experienced was physical rather than chemical in nature, as all samples exhibited the same Tg of around 91°C. This conclusion is further supported by the mass measurements presented in a previous section, which show that the samples returned to their original weight with no net loss after ageing, as previously discussed. The absence of phenomena such as leaching suggests that no chemical alterations occurred in the matrix, ruling out irreversible degradation.
+A further DSC test was carried out to compare samples in their virgin state, and during and after ageing, as well as after redrying. <span id='cite-_Ref195082609'></span>[[#_Ref195082609|Figure 5]] shows that material properties are recovered after drying, indicating that the ageing experienced was physical rather than chemical in nature, as all samples exhibited the same Tg of around 91°C. This conclusion is further supported by the mass measurements presented in a previous section, which show that the samples returned to their original weight with no net loss after ageing, as previously discussed. The absence of phenomena such as leaching suggests that no chemical alterations occurred in the matrix, ruling out irreversible degradatio
+[[File:Calorimetry 2 re.png|centre|thumb|715x715px]]
 <div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
-  [[Image:Draft_Mosciatti Urzua_152521725-image5-c.png|600px]] </div>
+  ''Figure 5: DSC of aged and redried samples (black line 1.5 hours, red line 5.5 hours) vs virgin (blue line).'' </div>
-−
-<div id="_Ref195082609" class="center" style="width: auto; margin-left: auto; margin-right: auto;">
 ''Figure 5: DSC of aged and redried samples (black line 1.5 hours, red line 5.5 hours) vs virgin (blue line).''</div>
-===4.4. Mechanical testing===
+===4.4. Mechanical tests' results===
 As mentioned before, four types of mechanical tests were carried out: shear, longitudinal and transversal tensile and compression.
 {| style="width: 100%;border-collapse: collapse;"

@@ Line 2: / Line 2: @@
-==Introduction==
+==1. Introduction==
 It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.
-==Materials selection==
+==2. Materials selection==
 Many constraints arise from the application. The material chosen must have particularly good mechanical properties, behave well in the particular environment, allow production methods adapted to the production of large parts and thick walls, and have interesting sustainable aspects.
@@ Line 14: / Line 14: @@
 For the reinforcement, multiple candidates were considered, including glass, carbon, basalt, aramid, and natural fibers. Choice was based on cost, moisture resistance, mechanical properties, and carbon footprint. While basalt fibers presented promising environmental and mechanical performance, glass fiber was selected as the optimal reinforcement due to its lower cost, widespread use in marine applications, and well-documented hydrothermal stability. Comparative studies indicated that both glass/epoxy and basalt/epoxy composites exhibit similar water absorption and post-immersion mechanical degradation. However, glass fiber offers higher commercial availability and requires less optimization at the fiber-matrix interface, making it the more reliable and practical choice for tidal blade applications [4][5][6]. Also, given its widespread use, it allows for more direct comparison of the resulting composite with known alternatives. Finally, given the characteristics of the resin, this choice does not hinder the sustainable character of the composite.
-==Thermal analysis==
+==3. Thermal analysis==
 The characterization effort began with the study of the resin itself.
@@ Line 32: / Line 32: @@
 In the first case, the Tg was found to be relatively low: 60ºC. Also, the exothermal peaks present at temperatures over the Tg give away residual curing. The postcured samples, instead, presented a significantly higher Tg of 92ºC, and no extra exothermal peaks, confirming complete curing was achieved.
-==Mechanical testing==
+==4. Mechanical testing==
 With the resin duly characterized, it’s time to face the main object of this paper, i.e. the mechanical characterization of the composite. Four types mechanical tests were performed (see [[Table 1]]):
@@ Line 77: / Line 77: @@
 <span id="_heading=h.j7zxjv78nabr"></span>
-===Diffusion Kinetics===
+===4.1. Diffusion Kinetics===
 Glass fiber composite plastic (GFRP) composite samples were aged by full immersion in deionised water. Full immersion was chosen to replicate the accelerated degradation mechanisms that can occur in the tidal blade due to prolonged seawater exposure. However, since seawater contains salts that hinder diffusion, moisture uptake is lower compared to pure water. For this reason, deionised water was selected in order to simplify the nature of the degradation reactions. It was also considered to represent a more extreme scenario and to enable a more conservative assessment of material degradation [7].
@@ Line 108: / Line 108: @@
 <span id='_Ref196826686'></span>
-===Void Content Study===
+===4.2. Void Content Study===
 The void content analysis aimed to assess the relationship between the amount of voids in the glass fibre laminates and the ageing environment to which they were exposed. Hence, void content was measured in composite samples both in their virgin state and after ageing.
@@ Line 124: / Line 124: @@
 ''Figure 4: Void content, %, as a function of ageing.''</div>
-===Thermal Recovery Post-Ageing===
+===4.3. Thermal Recovery Post-Ageing===
 A further DSC test was carried out to compare samples in their virgin state, and during and after ageing, as well as after redrying. <span id='cite-_Ref195082609'></span>[[#_Ref195082609|Figure 5]] shows that material properties are recovered after drying, indicating that the ageing experienced was physical rather than chemical in nature, as all samples exhibited the same Tg of around 91°C. This conclusion is further supported by the mass measurements presented in a previous section, which show that the samples returned to their original weight with no net loss after ageing, as previously discussed. The absence of phenomena such as leaching suggests that no chemical alterations occurred in the matrix, ruling out irreversible degradation.
@@ Line 134: / Line 134: @@
 ''Figure 5: DSC of aged and redried samples (black line 1.5 hours, red line 5.5 hours) vs virgin (blue line).''</div>
-===Mechanical testing===
+===4.4. Mechanical testing===
 As mentioned before, four types of mechanical tests were carried out: shear, longitudinal and transversal tensile and compression.
 {| style="width: 100%;border-collapse: collapse;"
@@ Line 195: / Line 195: @@
 ''Figure 6: Properties reduction due to ageing.''</div>
-====Longitudinal tensile tests====
+====4.4.1. Longitudinal tensile tests====
 Following ageing, a 6.5% reduction in the longitudinal Young’s modulus and a 14.5% decrease in tensile strength were recorded. The modest drop in stiffness suggests that the glass fibres largely retained their integrity. However, the more pronounced loss in tensile strength indicates that ageing significantly affected the matrix and the fibre/matrix interface. Moisture absorption and thermal exposure likely caused matrix plasticization, microcracking, or debonding at the interface, reducing the material’s tensile load-bearing capacity.
-====Transverse Tensile Strength====
+====4.4.2. Transverse Tensile Strength====
 In the transverse direction, the composite experienced a 28% decrease in Young’s modulus, reflecting a notable loss of stiffness. However, transverse tensile strength dropped by only 8%, suggesting that while the material became less stiff in this direction, its ultimate strength remained largely intact. This implies that ageing mainly affected the matrix and interface, reducing rigidity, without fully compromising the composite's ability to carry loads in the transverse direction.
@@ Line 210: / Line 210: @@
 Taken together, the 38% drop in compressive strength demonstrates that even physical ageing can substantially affect the structural performance of the material, particularly in systems with elevated porosity. With respect to the uncertainty surrounding the failure mode, electron microscopy of the fractured regions is a known method to gain insight into the underlying mechanisms [7].
-====Short-beam Shear - Interlaminar Shear Strength (ILSS)====
+====4.4.3. Short-beam Shear - Interlaminar Shear Strength (ILSS)====
 A 35% reduction in ILSS was observed after ageing. This significant drop indicates a considerable deterioration of the fibre/matrix interface, which plays a critical role in resisting interlaminar shear stresses. The combined effects of moisture absorption and thermal exposure weakened the adhesion between fibres and matrix, reducing the material's ability to efficiently transfer loads and compromising its shear strength across layers.
@@ Line 216: / Line 216: @@
 Interface weakening is a well-known ageing mechanism, as water tends to accumulate at the fibre/matrix bond, diminishing adhesion. The percentage loss in ILSS following ageing is comparable to that reported for conventional composites such as vinylester- or polyester-based GFRPs, especially considering the severe hydrothermal ageing conditions applied. Moreover, the material’s porosity likely contributed to water uptake, as higher void content is a recognised initiator of interfacial failure, facilitating water storage between fibre and matrix [8].
-===Conclusions===
+==5. Conclusions==
 The accelerated ageing study conducted on the glass fibre/Elium resin composite (GF/Elium) provided a comprehensive evaluation of the material’s performance under elevated humidity and temperature conditions. The results reflect a generally strong performance, even under a challenging scenario characterised by high void content (3.5–5.2%) and absence of surface protection.

@@ Line 34: / Line 34: @@
 ==Mechanical testing==
-With the resin duly characterized, it’s time to face the main object of this paper, i.e. the mechanical characterization of the composite. Four types mechanical tests were performed:
+With the resin duly characterized, it’s time to face the main object of this paper, i.e. the mechanical characterization of the composite. Four types mechanical tests were performed (see [[Table 1]]):
 {| style="width: 79%;margin: 1em auto 0.1em auto;border-collapse: collapse;"

@@ Line 4: / Line 4: @@
 ==Introduction==
-It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines’. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.
+It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.
 ==Materials selection==
@@ Line 20: / Line 20: @@
 Rheological and kinetic studies were carried out to ensure the behaviour of the resin was aligned with the data supplied by the manufacturer with satisfactory results.
-The kinetic study was later complemented by comparing cured and postcured unreinforced samples, with the objective of comparing their glass transition temperature (Tg). A differential scanning calorimetry (DSC) was carried out for both cases. The resulting calorimetry curves are shown in <span id='cite-_Ref196411681'></span>[[#_Ref196411681|Figure 1]] below.
+The kinetic study was later complemented by comparing cured and postcured unreinforced samples, with the objective of comparing their glass transition temperature (Tg). A differential scanning calorimetry (DSC) was carried out for both cases. The resulting calorimetry curves are shown in <span id='cite-_Ref196411681'></span>[[#_Ref196411681|Figure 1]].
 The red curve corresponds to samples that underwent 24 hours of ambient temperature curing. The samples from the black curve were cured in the same fashion, and then postcured for 3 hours at 80ºC
@@ Line 73: / Line 73: @@
 * Method: Manual lamination followed by curing in a vacuum press.
 * Lamination: 5 layers of biaxial glass fibre.
-* Conditions: 600 mbar vacuum
+* Conditions: 600 mbar vacuum.
-* Cure schedule: ambient cure – 24 h, post-cure: 3 h at 80°C
+* Cure schedule: ambient cure – 24 h, post-cure: 3 h at 80°C.
 <span id="_heading=h.j7zxjv78nabr"></span>
@@ Line 216: / Line 216: @@
 Interface weakening is a well-known ageing mechanism, as water tends to accumulate at the fibre/matrix bond, diminishing adhesion. The percentage loss in ILSS following ageing is comparable to that reported for conventional composites such as vinylester- or polyester-based GFRPs, especially considering the severe hydrothermal ageing conditions applied. Moreover, the material’s porosity likely contributed to water uptake, as higher void content is a recognised initiator of interfacial failure, facilitating water storage between fibre and matrix [8].
-===Final Conclusion===
+===Conclusions===
 The accelerated ageing study conducted on the glass fibre/Elium resin composite (GF/Elium) provided a comprehensive evaluation of the material’s performance under elevated humidity and temperature conditions. The results reflect a generally strong performance, even under a challenging scenario characterised by high void content (3.5–5.2%) and absence of surface protection.

← Older revision	Revision as of 11:40, 23 July 2025
(No difference)

← Older revision		Revision as of 08:25, 30 June 2025
Line 2:		Line 2:


−	==~~Intro~~==	+	==Introduction==

	It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines’. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.		It is estimated that, under the right conditions, ocean energy could contribute around 10% of EU power demand by 2050 [1], thus potentially playing a considerable role in its energy matrix in a future. <br/>Like in wind energy, the blades are the most challenging structural component, so the materials used are usually composites. This poses the problem of end-of-life disposal. It is estimated that the wind blade waste material in Europe, coming either from replacements or decommissioning, will be close to 150 000 tons in 2025 [2]. While much research exists for recyclability of wind turbine blades [3] not much has been done for tidal turbines’. <br/>This paper presents an overview of the initial stages of an ongoing research project on this very matter. We will discuss some key aspects of the choice of a suitable sustainable material and the extensive testing necessary to confirm its suitability to this end.

← Older revision	Revision as of 17:03, 30 April 2025
(No difference)

@@ Line 71: / Line 71: @@
 The test specimens have been manufactured under the following conditions to simulate the infusion process:
 * Method: Manual lamination followed by curing in a vacuum press.
-:* Method: Manual lamination followed by curing in a vacuum press.
+* Lamination: 5 layers of biaxial glass fibre.
 * Conditions: 600 mbar vacuum
-:* Lamination: 5 layers of biaxial glass fibre.
+* Cure schedule: ambient cure – 24 h, post-cure: 3 h at 80°C
+<span id="_heading=h.j7zxjv78nabr"></span>
-:* Conditions: 600 mbar vacuum
-−
-:* Cure schedule: ambient cure – 24 h, post-cure: 3 h at 80°C
-−
-<span id='_heading=h.j7zxjv78nabr'></span>
 ===Diffusion Kinetics===