| 11. |
- Costa, Sergio, 1987, et al.
(författare)
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Improvement and validation of a physically based model for the shear and transverse crushing of orthotropic composites
- 2019
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Ingår i: Journal of Composite Materials. - : SAGE Publications. - 1530-793X .- 0021-9983. ; 53:12, s. 1681-1696
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Tidskriftsartikel (refereegranskat)abstract
- This paper details a complete crush model for composite materials with focus on shear dominated crushing under a three-dimensional stress state. The damage evolution laws and final failure strain conditions are based on data extracted from shear experiments. The main advantages of the current model include the following: no need to measure the fracture toughness in shear and transverse compression, mesh objectivity without the need for a regular mesh and finite element characteristic length, a pressure dependency of the nonlinear shear response, accounting for load reversal and some orthotropic effects (making the model suitable for noncrimp fabric composites). The model is validated against a range of relevant experiments, namely a through-the-thickness compression specimen and a flat crush coupon with the fibres oriented at 45° and 90° to the load. Damage growth mechanisms, orientation of the fracture plane, nonlinear evolution of Poisson's ratio and energy absorption are accurately predicted.
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| 12. |
- Costa, Sergio, et al.
(författare)
-
Numerical validation of an improved model for the shearing and transverse crushingof orthotropic composites
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper details a complete crush model for composite materials with focus on shear dominated crushing under a3D stress state. The damage evolution laws and nal failure strain conditions are based on data extracted from shearexperiments. The main advantages of the current model are: no need to measure the fracture toughness in shear andtransverse compression, mesh objectivity without the need for a regular mesh and nite element characteristic length, apressure dependency of the shear response, account for load reversal and for some orthotropic eects (making the modelsuitable for Non-Crimp Fabric composites). The model is validated against a range of relevant experiments, namely athrough-the-thickness compression specimen and a at crush coupon with the bres oriented at 45 and 90 degrees to theload. Damage growth mechanisms, orientation of the fracture plane, nonlinear evolution of Poisson's ratio and energyabsorption are accurately predicted.
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| 13. |
- Costa, Sergio, 1987, et al.
(författare)
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Validation of a novel model for the compressive response of FRP: Numerical simulation
- 2017
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Ingår i: ICCM International Conferences on Composite Materials. ; 2017-August
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Konferensbidrag (refereegranskat)abstract
- A progressive damage model for matrix compression is complemented with matrix tension in a physically based manner. The interaction of damage mechanisms undergoes a preliminary validation using single elements. The crushing response is validated with two different flat specimens with the fibres oriented transversely and at 45 degrees to the load. The model combines friction with damage to model the shear response accurately, which is necessary for reliable crush simulations. The behaviour in tension is history dependent, i.e. the model accounts for the stiffness reduction and strength to carry load in tension when previously damaged occurs in compression. The validation is performed against different tests showing the reliability of the model for different fibre orientation, specimen geometry and multiaxial loading scenarios. The crush response is well captured as well as the geometry and location of the different damage mechanisms.
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| 14. |
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| 15. |
- Francis, Sachin, 1991, et al.
(författare)
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Characterisation of tape-based carbon fibre thermoplastic discontinuous composites for energy absorption
- 2021
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Ingår i: Plastics, rubber and composites. - : Taylor and Francis Ltd.. - 1465-8011 .- 1743-2898. ; 50:7, s. 351-
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Tidskriftsartikel (refereegranskat)abstract
- Tape-based discontinuous composite is a relatively new type of composite material that offers improved mechanical properties for similar process-ability compared to Sheet Moulding Compound or Bulk Moulding Compound. This makes it potentially attractive for the automotive industry. In this paper, a thin-ply carbon fibre reinforced polypropylene-based discontinuous composite is studied. Mechanical tests are performed to obtain the tensile, compression and shear behaviour of the material. The energy absorption via tearing is also studied to assess the suitability of the material for energy absorption applications, such as crash-boxes. The tearing test results show a large degree of plastic deformation and an advancing damage front leading to higher specific energy absorption via tearing compared to conventional composite materials. © 2021 The Author(s).
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| 16. |
- Wilhelmsson, Dennis, 1980, et al.
(författare)
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Compressive strength assessment of a CFRP aero-engine component – An approach based on measured fibre misalignment angles
- 2019
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Ingår i: Composite structures. - : Elsevier Ltd. - 0263-8223 .- 1879-1085. ; 233
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we apply a recently developed methodology to assess the compressive strength of an aero-engine component based on measured fibre misalignment angles. The component is a fan outlet guide vane made from a carbon fibre reinforced polymer, which was manufactured and tested by GKN Aerospace in Sweden. The main novelty with this work is that kink-band formation is predicted from measurements of fibre misalignment angles with high spatial resolution in a real component. In addition, we validate the recently published “defect severity model” on unidirectional specimens of the same material system as the aerospace component. We confirm high accuracy of the model for prediction of compressive strength on unidirectional composite laminates. Further work is however needed to extend the methodology for cases where progressive damage leads to final failure.
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