The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Xiaojing Gong - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of the influence of Ply orientation on DCB mode-I delamination behavior by using multidirectional fully isotropic carbon/epoxy laminates
Composite Structures, 2017Co-Authors: M.s. Bin Mohamed Rehan, J. Rousseau, S. Fontaine, Xiaojing GongAbstract:The influence of Ply orientation on the resistance to mode I delamination of multidirectional composite laminates can be assessed by Double Cantilever Beam (DCB) tests. However, one difficulty is to uncouple the global and local effects due to the stacking sequence, which is necessary for a conclusive analysis. In the present work six multidirectional DCB specimens were designed so as to obtain an uncoupled fully isotropic elastic behavior, with the same properties for the entire laminate and the two sub laminates separated by the pre-crack at mid-plane. These specimens have different Ply orientations, but their elastic properties are exactly the same. Hence differences in mode I delamination behavior are only due to local fiber orientation effects. Experimental results show that the measured toughness at the crack initiation decreases with both Adjacent and sub-Adjacent Ply angles. During the crack propagation, the plateau value of the R-curve increases with the Ply angle of Adjacent plies.
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effet de l orientation des fibres des plis Adjacents sur la resistance au delaminage en mode i pur effect of the fibre s orientation of Adjacent Ply on pure mode i fracture toughness
JNC 16, 2009Co-Authors: Xiaojing Gong, Anita HurezAbstract:Ce travail concerne l'etude de l'effet de l'orientation des fibres des plis Adjacents a la fissure dans une eprouvette DCB (Double Cantilever Beam) sur la resistance au delaminage en mode I pur. Afin d'isoler l'influence de l'orientation l'etude porte sur des stratifies particuliers ayant tous les memes matrices de comportement global A B D. Les resultats experimentaux montrent une grande variation de resistance au delaminage GIC et des courbes R selon l'orientation des plis situes de part et d'autre du plan de fissure. Une modelisation par elements finis permet de mettre en evidence l'importance de l'etat de contraintes locales et donc de l'endommagement au voisinage du fond de fissure
George S. Springer - One of the best experts on this subject based on the ideXlab platform.
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Delaminations in composite plates under transverse impact loads — Experimental results
Composite Structures, 2003Co-Authors: Scott R. Finn, Ye-fei He, George S. SpringerAbstract:Abstract Tests were performed measuring the locations and geometries of delaminations in Fiberite T300/976 graphite/epoxy, Fiberite IM7/977-2 graphite-toughened epoxy, and ICI APC-2 graphite/PEEK plates subjected to transverse impact loads. The data provide specific information on the effects of impactor velocity, impactor mass, material, thickness of back Ply group, difference in fiber orientation between Adjacent Ply groups, plate thickness, and impactor nose radius. The data were compared to the results of the Finn-Springer model. The model was found to describe the data with reasonable accuracy.
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Composite Plates Impact Damage: An Atlas
1991Co-Authors: Scott R. Finn, George S. SpringerAbstract:The present volume on impact damage in composite plates presents an extensive compendium of visual and graphic data regarding a variety of material and impactor parameters. The photographs are taken with X-ray and C-scan imaging in conjunction with a dye penetrant to show matrix cracks and delaminations. Impact and static-loading tests are performed on plates of graphite-epoxy, graphite-toughened epoxy, and graphite-PEEK materials. The images are presented to yield specific visual data regarding such parameters as impactor velocity, thickness of the back Ply group, impactor nose radius, and the effects of multiple delaminations. The images are grouped in eight subsets that correspond to parameters including plate length, material, and the difference in fiber orientation between Adjacent Ply groups. This substantial volume represents a systematic effort to study the effects of several material parameters on impact damage.
Scott R. Finn - One of the best experts on this subject based on the ideXlab platform.
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Delaminations in composite plates under transverse impact loads — Experimental results
Composite Structures, 2003Co-Authors: Scott R. Finn, Ye-fei He, George S. SpringerAbstract:Abstract Tests were performed measuring the locations and geometries of delaminations in Fiberite T300/976 graphite/epoxy, Fiberite IM7/977-2 graphite-toughened epoxy, and ICI APC-2 graphite/PEEK plates subjected to transverse impact loads. The data provide specific information on the effects of impactor velocity, impactor mass, material, thickness of back Ply group, difference in fiber orientation between Adjacent Ply groups, plate thickness, and impactor nose radius. The data were compared to the results of the Finn-Springer model. The model was found to describe the data with reasonable accuracy.
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Composite Plates Impact Damage: An Atlas
1991Co-Authors: Scott R. Finn, George S. SpringerAbstract:The present volume on impact damage in composite plates presents an extensive compendium of visual and graphic data regarding a variety of material and impactor parameters. The photographs are taken with X-ray and C-scan imaging in conjunction with a dye penetrant to show matrix cracks and delaminations. Impact and static-loading tests are performed on plates of graphite-epoxy, graphite-toughened epoxy, and graphite-PEEK materials. The images are presented to yield specific visual data regarding such parameters as impactor velocity, thickness of the back Ply group, impactor nose radius, and the effects of multiple delaminations. The images are grouped in eight subsets that correspond to parameters including plate length, material, and the difference in fiber orientation between Adjacent Ply groups. This substantial volume represents a systematic effort to study the effects of several material parameters on impact damage.
A.s.d. Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects of a 90° Ply on matrix cracks and edge delamination in composite laminates
Composites Science and Technology, 2003Co-Authors: Wen S. Chan, A.s.d. WangAbstract:Abstract This study confirms the fact that a special toughened 90° Ply, when serving as the core layer in cross-plied and angle-plied laminates, has a definite effect on matrix cracking and threshold delamination in the laminate. The 90° oly of the IM6/5245C graphite/epoxy and S2/5245C glass/epoxy laminates was hybridized into IM6/3501-6 graphite/epoxy laminates for this study. The results clearly indicate that the hybridized laminate can withstand significantly higher loads before the onset of laminate splitting, delamination, and final failure. The delay in splitting and delamination is attributed to a reduction in the mismatch of both moduli and thermal expansion coefficient in the direction normal to the free edge at the interface between the 90° Ply and its Adjacent Ply.
Takashi Ishikawa - One of the best experts on this subject based on the ideXlab platform.
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parametric analysis on the Adjacent Ply crack formation in laminated structures for cryogenic propellant tank application
45th AIAA ASME ASCE AHS ASC Structures Structural Dynamics & Materials Conference, 2004Co-Authors: Tomohiro Yokozeki, Takahira Aoki, Takashi IshikawaAbstract:A parametric-oriented methodology for stress analysis of laminated structures containing obliquely-crossed matrix cracks is presented and applied to the finite element formulation. An oblique coordinate system along the fiber directions of the obliquely-crossed cracked plies is defined in conjunction with the derivation of corresponding covariant displacement/strain components and contravariant force/stress components as a function of oblique angle. It is identified that problem with obliquely-crossed geometry can be transformed to the orthogonally-crossed problem using the corresponding oblique components, which enables parametric analyses for various oblique angles using a single discrete model with orthogonal geometry. Laminates with traversing matrix cracks in one Ply and oblique micro-formed cracks in the Adjacent Ply are parametrically analyzed under thermomechanical loadings. The susceptibility of the micro-formed crack propagation in the fiber direction of the Adjacent Ply and further induction of matrix cracks in other plies is discussed under various conditions of Adjacent Ply angle, crack length in the Adjacent Ply, crack densities, etc. Effects of cryogenic temperature on the crack conformation in the Adjacent Ply are also investigated for cryogenic composite propellant tank application.
