| 1. |
- André, Alann, et al.
(författare)
-
Cirkulärt omhändertagande av solcellspaneler och vindturbinblad för vindkraftverk
- 2024
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I regleringsbrevet för 2023 fick Energimyndigheten i uppdrag av regeringen att utreda hur solcellspaneler och vindturbinblad till vindkraftverk i högre utsträckning ska kunna tas om hand på ett giftfritt och cirkulärt sätt i enlighet med avfallshierarkin. Redovisningen av detta regeringsuppdrag, rapporten Från avfall till resurs – Förslag för en mer cirkulär hantering av solcellspaneler och vindturbinblad, ER 2024:11, baseras på denna underlagsrapport som har tagits fram av forskningsinstitutet RISE på uppdrag av Energimyndigheten. Analyser, slutsatser och förslag/rekommendationer som framförs i rapporten är författarnas egna.En fortsatt utbyggnad av fossilfri elproduktion är av stor vikt för att vi ska kunna nå Sveriges energi- och klimatmål. För att utbyggnaden i sig ska vara hållbar är det viktigt att vi redan nu planerar för hur avfallet från dessa elproduktionsanläggningar ska förebyggas, minimeras och sedan hanteras.Det finns redan i dagsläget aktörer som har utvecklat och håller på att utveckla ett flertal olika lösningar för ökad cirkularitet. Dessa möjligheter kan tas tillvara och främjas genom regelbunden kartläggning och genom att arbeta gemensamt inom EU. Genom ett sådant arbete finns det också större möjligheter att etablera industriella värdekedjor i Sverige för hanteringen av avfallet från solcellspaneler och vindturbinblad.En cirkulär hantering av avfall ger ett betydligt mindre avtryck på miljön än det som en linjär hantering ger upphov till. Det är viktigt att de aktörer som tillhandahåller fossilfri elproduktion tar ansvar under hela livscykeln och att det finns goda förutsättningar för aktörerna att göra det.
|
|
| 2. |
- André, Alann, et al.
(författare)
-
Digital platform for managementof EoL windturbine blades : Rekovind 2 - WP2
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Rekovind2 project, financed by the Swedish Energy Agency, focuses on digitizing wind turbine blade streams for reuse and recycling. This is of the utmost importance to enable new, more circular technical solutions that can replace today’s non-sustainable recycling, i.e. landfill and incineration of wind turbine blades. In this report, the work carried out to map the wind turbine blades in service in Sweden is presented. The digital platform intended to make possible the re-use of blades reaching end-of-life is build around key features that will be required for re-use: blade database with all needed informations on the blade (age, damages, material, model, ...), map with blades geolocation, digital tool to help blade processing such as cutting, and information on what can be done with EoL blades.
|
|
| 3. |
- Bru, Thomas, 1990
(författare)
-
Behaviour and material properties of composites for crash modelling
- 2016
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The transport industry must find solutions to reduce its impact on climate change. A promising way to reduce the weight of vehicles and therefore to reduce the CO2 emissions is to introduce components made of lightweight composite materials, in particular laminated carbon fibre reinforced polymers (CFRPs). Aside from the new design possibilities for lighter vehicle structures, CFRPs can also potentially offer large improvements in terms of energy absorption capabilities in comparison to traditional crash components made of metals. During crushing of composites, a large amount of energy is absorbed through stable progressive failure of the material. The crushing process is a complex phenomenon because it is driven by the combination of many failure mechanisms and frictional effects. A limited amount of research has been performed on crushing of composites, mainly because crashworthiness is not a critical requirement in the aerospace industry (the predominant market for advanced composites today). As a result, there is today no reliable numerical tool to predict the crashworthiness of CFRP structures, which is a hindrance to the introduction of composite materials in mass-produced automobiles. Joint research efforts from both numerical and experimental perspectives are needed to fill this void and reach the goal of reliable crash predictions of composite vehicles. The focus of this thesis is on a material characterisation strategy for crash modelling of composites. An experimental methodology is developed to provide relevant and accurate input to a physically-based material model for crash, currently being developed in parallel to this thesis. The material selected for this research is a CFRP with non-crimp fabric (NCF) reinforcements. The first step in the material characterisation is to extract the different strengths and stiffnesses of the material, which requires dedicated tests because of the orthotropic nature of NCF composites. In a second step, more specific inputs to ply damage models for progressive failure are extracted from experiments. Those parameters are (1) damage evolution laws, identified from Iosipescu shear tests, and (2) the longitudinal and the transverse crushing behaviour of unidirectional laminates, extracted from relatively simple crush tests on flat specimens.
|
|
| 4. |
- Bru, Thomas, 1990, et al.
(författare)
-
Biaxial transverse compression testing for a fibre reinforced polymer material
- 2020
-
Ingår i: ECCM 2018 - 18th European Conference on Composite Materials.
-
Konferensbidrag (refereegranskat)abstract
- Unidirectional laminates have been tested under uniaxial transverse compression and under biaxial transverse compression. Failure occurred by shear in an inclined failure plane parallel to the fibres. The transverse shear response of the material on the failure plane was evaluated from the tests. In the biaxial tests, the failure load was considerably higher than in the uniaxial tests. For a given transverse shear strain the transverse shear stress was also higher in the case of biaxial compression. It is also shown that using waisted specimens instead of prismatic specimens does not seem to bring noticeable benefits for through-thickness uniaxial compression tests. The experimental results presented here are important input to the development and the validation of damage models of fibre reinforced polymer materials accounting for the matrix nonlinear response in shear and compression.
|
|
| 5. |
- Bru, Thomas, et al.
(författare)
-
Characterisation of the mechanical and fracture properties of a uni-weave carbon fibre/epoxy non-crimp fabric composite
- 2016
-
Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 6, s. 680-695
-
Tidskriftsartikel (refereegranskat)abstract
- A complete database of the mechanical properties of an epoxy polymer reinforced with uni-weave carbon fibre non-crimp fabric (NCF) is established. In-plane and through-the-thickness tests were performed on unidirectional laminates under normal loading and shear loading. The response under cyclic shear loading was also measured. The material has been characterised in terms of stiffness, strength, and failure features for the different loading cases. The critical energy release rates associated with different failure modes in the material were measured from interlaminar and translaminar fracture toughness tests. The stress–strain data of the tensile, compressive, and shear test specimens are included. The load–deflection data for all fracture toughness tests are also included. The database can be used in the development and validation of analytical and numerical models of fibre reinforced plastics (FRPs), in particular FRPs with NCF reinforcements.
|
|
| 6. |
- Bru, Thomas, et al.
(författare)
-
Development of a test method for evaluating the crushing behaviour of unidirectional laminates
- 2017
-
Ingår i: Journal of composite materials. - : SAGE Publications Ltd. - 0021-9983 .- 1530-793X. ; 51:29, s. 4041-4051
-
Tidskriftsartikel (refereegranskat)abstract
- More fundamental test methods are needed to assist the development of physically based and truly predictive simulation tools for composite materials under crash conditions. In this paper, a unidirectional flat specimen that can be used to validate the predicted behaviour from a simulation to the physical behaviour in the experiment is developed. A systematic experimental investigation is conducted to evaluate the influence of the trigger geometry on the crushing response by selecting two trigger types and different trigger angles. For longitudinal crushing, the traditional bevel trigger leads to out-of-plane failure by splaying with a limited amount of in-plane fracture, while the proposed trigger achieves a high amount of compressive fragmentation failure. For transverse crushing, the symmetry of the proposed new trigger improves the specimen stability during the crushing process. It is also observed that the weft threads of the unidirectional fabric reinforcement used for the tests have a strong influence on the longitudinal crushing response. The boundary conditions of the test and the information on the specimen failure gleaned from video recordings and microscopic inspections are discussed in order to facilitate a future correlation with modelling results.
|
|
| 7. |
- Bru, Thomas, 1990
(författare)
-
Material characterisation for crash modelling of composites
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The transport industry must find solutions to reduce its impact on climate change. A promising way to reduce the weight of vehicles and therefore to reduce the CO2 emissions is to introduce components made of lightweight composite materials, in particular carbon fibre reinforced plastics (CFRPs). Aside from the new design possibilities for lighter vehicle structures, CFRPs can also potentially offer improvements in terms of crash performance in comparison to traditional metallic structures. During crushing of composite structures, energy is absorbed through the stable progressive failure of the structure. The crushing process is a complex phenomenon involving the interaction of different competing failure mechanisms and frictional interactions taking place at different scales in the material. Today there is no reliable numerical tool to predict the behaviour of composite structures in crash scenarios, which is a hindrance to the introduction of composite materials in mass-produced vehicles. Joint research efforts from both numerical and experimental perspectives are needed to fill this gap. In this doctoral thesis experiments are carried out to extract relevant material properties for crash modelling, and to assist in the development and the validation of numerical models as a first step of a building block approach with increasing structural complexity. The material selected for the study is a carbon fibre/epoxy uni-weave non-crimp fabric (NCF) composite. The first step in the material characterisation is to extract the different strengths and stiffnesses of the material, which requires dedicated tests because of the orthotropic nature of NCFs. Because several compressive failure mechanisms are driven by the shearing of the matrix polymer, a methodology is presented to extract the damage evolution laws from Iosipescu shear tests and indirect shear tests (uniaxial and biaxial compression tests). A quasi-static test method that uses crush coupons of simple geometry is proposed to measure the crush stress of composite plies for different fibre orientations and to characterise the associated crushing mechanisms. The experimental results of the crush coupons are then compared to blind predictions from finite element simulations to assess the predictive capabilities of a ply-based material model coupling damage and friction in a continuum damage approach. This material model is currently being developed in parallel to this thesis. Its aim is to pre-emptively simulate structural tests in order to optimise the design of crashworthy structures and to limit the number of physical tests.
|
|
| 8. |
- Bru, Thomas, et al.
(författare)
-
Use of the Iosipescu test for the identification of shear damage evolution laws of an orthotropic composite
- 2017
-
Ingår i: Composite structures. - : Elsevier BV. - 0263-8223 .- 1879-1085. ; 174, s. 319-328
-
Tidskriftsartikel (refereegranskat)abstract
- The experimental evaluation of the shear response of fibre-reinforced plies is a requirement for accurate material models predicting progressive damage. In the first part of the paper, the quality of the Iosipescu shear test is investigated with full-field strain measurements and finite element analyses. In the second part, the in-plane and through-thickness shear response of an orthotropic carbon/epoxy uni-weave non-crimp fabric composite are compared, and the stress–strain curves used as input for two continuum damage mechanics models. Both models were able to predict accurately the nonlinear shear behaviour of the material. The model parameters and the damage evolution laws could easily be extracted from cyclic Iosipescu tests.
|
|
| 9. |
- Bru, Thomas, et al.
(författare)
-
Validation of a novel model for the compressive response of FRP:experiments with different fibre orientations
- 2017
-
Konferensbidrag (refereegranskat)abstract
- Crush tests have been performed on flat unidirectional non-crimp fabric (NCF) coupons with differentfibre orientations as part of the validation of a ply-based damage model for crash. The fibre off-axisangle with respect to the crushing direction ranged from 0º to 90°. The results of the tests indicate thatthe crush stress remains unchanged for off-axis angles between 0° and 15°. The failure mode in thesespecimens was out-of-plane kinking. For 20° and 25° off-axis angles the crush stress dropped 20% andevidence of out-of-plane kinking were harder to find. For 45° off-axis angle a network of matrixcracks develops in the specimen and for 90° off-axis angle a brittle shear failure is observed. It issuggested that the out-of-plane kinking is promoted because of the natural waviness of NCF materialsand that the high in-plane shear stress generated from 20-25° off-axis loading results in a transitionfrom out-of-plane kinking to in-plane kinking. These hypotheses need, however, to be verified by anextended failure analysis of the crush specimens.
|
|
| 10. |
- Bru, Thomas, 1990, et al.
(författare)
-
Validation of a novel model for the compressive response of FRP: experiments with different fibre orientations
- 2017
-
Ingår i: ICCM International Conferences on Composite Materials. ; 2017
-
Konferensbidrag (refereegranskat)abstract
- Crush tests have been performed on flat unidirectional non-crimp fabric (NCF) coupons with different fibre orientations as part of the validation of a ply-based damage model for crash. The fibre off-axis angle with respect to the crushing direction ranged from 0º to 90°. The results of the tests indicate that the crush stress remains unchanged for off-axis angles between 0° and 15°. The failure mode in these specimens was out-of-plane kinking. For 20° and 25° off-axis angles the crush stress dropped 20% and evidence of out-of-plane kinking were harder to find. For 45° off-axis angle a network of matrix cracks develops in the specimen and for 90° off-axis angle a brittle shear failure is observed. It is suggested that the out-of-plane kinking is promoted because of the natural waviness of NCF materials and that the high in-plane shear stress generated from 20-25° off-axis loading results in a transition from out-of-plane kinking to in-plane kinking. These hypotheses need, however, to be verified by an extended failure analysis of the crush specimens.
|
|
