The Experts below are selected from a list of 507 Experts worldwide ranked by ideXlab platform
Lincy Pyl - One of the best experts on this subject based on the ideXlab platform.
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quasi static crush modelling of carbon epoxy composites with discontinuous galerkin anisotropic extrinsic cohesive law method
Composite Structures, 2019Co-Authors: Xing Liu, Danny Van Hemelrijck, Lincy PylAbstract:Abstract Carbon/epoxy composites demonstrate significant promising improvements of weight to performance in the automotive industry. However, the design of carbon/epoxy composite components for crashworthiness remains challenging and normally requires laborious and repeated experimental work. This study adopts a predictive crush model of carbon/epoxy composites, which can partially replace the experimental work. The discontinuous Galerkin (DG) method with extrinsic cohesive laws is employed to simulate the failure patterns in the composite structures. The application of DG distinguishes the fracture model from the conventional approach where preset cohesive elements are used on the location where Cracks are expected. The mixed mode cohesive laws are used to simulate the delamination between each layer. To capture different Crack propagations in different layups, the anisotropic cohesive law is used to simulate the Intralaminar Crack propagation in composites. To verify the adopted model, circular composite tube specimens with different layups have been simulated and compared with tests under quasi-static crush loadings. The comparisons of numerical results with experimental data show that the DG crush model can reproduce the experimental results with relatively high accuracy.
Xing Liu - One of the best experts on this subject based on the ideXlab platform.
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quasi static crush modelling of carbon epoxy composites with discontinuous galerkin anisotropic extrinsic cohesive law method
Composite Structures, 2019Co-Authors: Xing Liu, Danny Van Hemelrijck, Lincy PylAbstract:Abstract Carbon/epoxy composites demonstrate significant promising improvements of weight to performance in the automotive industry. However, the design of carbon/epoxy composite components for crashworthiness remains challenging and normally requires laborious and repeated experimental work. This study adopts a predictive crush model of carbon/epoxy composites, which can partially replace the experimental work. The discontinuous Galerkin (DG) method with extrinsic cohesive laws is employed to simulate the failure patterns in the composite structures. The application of DG distinguishes the fracture model from the conventional approach where preset cohesive elements are used on the location where Cracks are expected. The mixed mode cohesive laws are used to simulate the delamination between each layer. To capture different Crack propagations in different layups, the anisotropic cohesive law is used to simulate the Intralaminar Crack propagation in composites. To verify the adopted model, circular composite tube specimens with different layups have been simulated and compared with tests under quasi-static crush loadings. The comparisons of numerical results with experimental data show that the DG crush model can reproduce the experimental results with relatively high accuracy.
Masaaki Nishikawa - One of the best experts on this subject based on the ideXlab platform.
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Intralaminar fatigue Crack growth properties of conventional and interlayer toughened CFRP laminate under mode I loading
Composites Part A: Applied Science and Manufacturing, 2015Co-Authors: N. Sato, Masaki Hojo, Masaaki NishikawaAbstract:Abstract Intralaminar and interlaminar fatigue Crack growth behaviours under mode I loading were investigated with conventional and interlayer toughened unidirectional CFRP laminates. For Intralaminar Crack growth tests, initial defects were introduced using “Intralaminar film insertion method”, in which a release film is inserted inside a single lamina prepreg. A fatigue test under a constant maximum energy release rate, Gmax, was carried out using DCB specimens. It was found that the Intralaminar fatigue Crack growth property of the interlayer toughened CFRP laminates was the same as that of the conventional CFRP laminates. For the interlayer toughened CFRP laminates, the Gmax with a given Crack growth rate, da/dN, was much lower for Intralaminar Crack growth than for interlaminar Crack growth. The da/dN-Gmax curve at zero Crack extension, Δa = 0, which was estimated by extrapolating the da/dN-Δa relationship, was not affected by bridging fibres, and most conservative for the interlayer toughened CFRP laminates.
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Intralaminar fatigue Crack growth properties of conventional and interlayer toughened cfrp laminate under mode i loading part a applied science and manufacturing
Composites, 2015Co-Authors: N. Sato, Masaki Hojo, Masaaki NishikawaAbstract:Intralaminar and interlaminar fatigue Crack growth behaviours under mode I loading were investigated with conventional and interlayer toughened unidirectional CFRP laminates. For Intralaminar Crack growth tests, initial defects were introduced using “Intralaminar film insertion method”, in which a release film is inserted inside a single lamina prepreg. A fatigue test under a constant maximum energy release rate, Gmax, was carried out using DCB specimens. It was found that the Intralaminar fatigue Crack growth property of the interlayer toughened CFRP laminates was the same as that of the conventional CFRP laminates. For the interlayer toughened CFRP laminates, the Gmax with a given Crack growth rate, da/dN, was much lower for Intralaminar Crack growth than for interlaminar Crack growth. The da/dN-Gmax curve at zero Crack extension, Δa=0, which was estimated by extrapolating the da/dN-Δa relationship, was not affected by bridging fibres, and most conservative for the interlayer toughened CFRP laminates.
Danny Van Hemelrijck - One of the best experts on this subject based on the ideXlab platform.
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quasi static crush modelling of carbon epoxy composites with discontinuous galerkin anisotropic extrinsic cohesive law method
Composite Structures, 2019Co-Authors: Xing Liu, Danny Van Hemelrijck, Lincy PylAbstract:Abstract Carbon/epoxy composites demonstrate significant promising improvements of weight to performance in the automotive industry. However, the design of carbon/epoxy composite components for crashworthiness remains challenging and normally requires laborious and repeated experimental work. This study adopts a predictive crush model of carbon/epoxy composites, which can partially replace the experimental work. The discontinuous Galerkin (DG) method with extrinsic cohesive laws is employed to simulate the failure patterns in the composite structures. The application of DG distinguishes the fracture model from the conventional approach where preset cohesive elements are used on the location where Cracks are expected. The mixed mode cohesive laws are used to simulate the delamination between each layer. To capture different Crack propagations in different layups, the anisotropic cohesive law is used to simulate the Intralaminar Crack propagation in composites. To verify the adopted model, circular composite tube specimens with different layups have been simulated and compared with tests under quasi-static crush loadings. The comparisons of numerical results with experimental data show that the DG crush model can reproduce the experimental results with relatively high accuracy.
Esben Lindgaard - One of the best experts on this subject based on the ideXlab platform.
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effect of variable amplitude block loading on Intralaminar Crack initiation and propagation in multidirectional gfrp laminate
Composites Part B-engineering, 2021Co-Authors: Jens Jakob Bender, Brian Lau Verndal Bak, Simon Mosbjerg Jensen, Esben LindgaardAbstract:Abstract Studies have shown that the fatigue life of multidirectional laminated fibre composites is reduced for variable amplitude block loading and random load spectra compared to constant amplitude loading. One of the hypotheses in the literature for this is a cycle mix effect that causes extra damage each time the load increases i.e. load amplitude or mean load. However, no explanation for this effect has been provided in the literature. This work aims at identifying the reasons for the reduced fatigue life of variable amplitude block loading tests compared to constant amplitude loading tests. This is done through white light imaging which is used to detect when Intralaminar Cracks occur in the off-axis layers and from this to determine Crack density evolution, Crack density rates, as well as initiation and propagation of Intralaminar Cracks contributing to the total Crack density. Combined, these parameters show that there is a slow transition from a high Crack density rate in the high load blocks to a lower Crack density rate in the low load blocks. The Crack density rate in the low load blocks in a variable amplitude loading test is higher than in a constant amplitude loading test at similar damage states. Finally, the high load blocks initiate new Cracks in each block but they also cause all existing Cracks to continue their propagation in subsequent low load blocks at increased rates. In conclusion, there is evidence that the block changes from high to low loads cause increased Crack propagation in subsequent low load cycles, which is an important contribution to explain the damaging effect of cycle mixing.