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Chao Zhang - One of the best experts on this subject based on the ideXlab platform.
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modelling fracture and delamination in composite laminates Energy Release Rate and interface stress
Composite Structures, 2018Co-Authors: J L Curielsosa, Chao Zhang, B TafazzolimoghaddamAbstract:Abstract This article presents an approach for modelling fracture and delamination, based on the partition of finite elements and on the Energy Release Rate due to crack propagation in cross-ply laminates. The Energy Release Rate is implemented within an Extended Finite Element Method (XFEM) framework. This approach is enabling the prediction of delamination propagation without pre-allocating damage zones. No element deletion techniques were used either. Mesh refinement was not needed for the propagation of cracks. Virtual testing of transverse cracks – eventually triggering delamination in cross-ply laminates – is presented to show the technique efficiency. Thus, a maximum Energy Release Rate of 0.9 kJ / m 2 is found for a transverse crack within [ 0 0 , 90 0 ] s laminate. When maximum Energy Release Rate is reached, delamination in the { 0 0 / 90 0 } interface is triggered. Furthermore, delamination in a composite double cantilever beam is simulated and presented in some detail. The results were compared with experimental outputs and/or by other numerical means showing an excellent correlation.
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modelling fracture and delamination in composite laminates Energy Release Rate and interface stress
Composite Structures, 2018Co-Authors: J L Curielsosa, Chao Zhang, B TafazzolimoghaddamAbstract:This article presents an approach for modelling fracture and delamination, based on the partition of finite elements and on the Energy Release Rate due to crack propagation in cross-ply laminates. The Energy Release Rate is implemented within an Extended Finite Element Method (XFEM) framework. This approach is enabling the prediction of delamination propagation without pre-allocating damage zones. No element deletion techniques were used either. Mesh refinement was not needed for the propagation of cracks. Virtual testing of transverse cracks – eventually triggering delamination in cross-ply laminates – is presented to show the technique efficiency. Thus, a maximum Energy Release Rate of 0.9kJ/m 2 is found for a transverse crack within [0 0 ,90 0 ] s laminate. When maximum Energy Release Rate is reached, delamination in the {0 0 /90 0 } interface is triggered. Furthermore, delamination in a composite double cantilever beam is simulated and presented in some detail. The results were compared with experimental outputs and/or by other numerical means showing an excellent correlation.
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Energy Release Rate and phase angle of delamination in sandwich beams and symmetric adhesively bonded joints
International Journal of Solids and Structures, 2009Co-Authors: Jialai Wang, Chao ZhangAbstract:Delamination in sandwich structures along the interface between the face sheet and the core, or along the adherend/adhesive interface in adhesively bonded joints, is one of the most common failure modes of this type of tri-layer structure. This delamination is usually modeled as an interface crack problem, for which the Energy Release Rate and phase angle can be calculated using interface fracture mechanics solutions. Existing interface fracture mechanics solutions, however, ignore the effect of transverse shear deformation, which can be significant for short crack. In an effort to overcome this shortcoming, this study presents new analytical solutions for the Energy Release Rate and for the phase angle of the interface crack in sandwich structures or adhesively bonded joints. Since the new solutions incorpoRate relative rotation at the tip of the delamination, transverse shear effects are taken into account in this study. Typical delaminated sandwich and adhesively bonded joint specimens are analyzed by using the new solutions, as well as by the existing solutions. The Energy Release Rate predicted by the present model agrees very well with that predicted by FEA, and furthermore it is considerably more accuRate relative to existing models. As the existing model neglects the transverse shear force, it underestimates the total Energy Release Rate. A stress field analysis is also conducted in this study in order to clarify some misunderstandings in the literature on the determination of the phase angle of adhesively bonded joints using an interface stress-based method.
M Chabchoub - One of the best experts on this subject based on the ideXlab platform.
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Numerical estimation of the mode I strain Energy Release Rate in woven-ply thermoplastic-based composites at high temperature based on Gθ method
Theoretical and Applied Fracture Mechanics, 2019Co-Authors: M Chabchoub, B Vieille, Rostand Moutou PittiAbstract:The present work was aimed at estimating the mode I strain Energy Release Rate at crack initiation in woven-ply thermoplastic (TP) based laminates at high temperature T>T g . A linear spectral viscoelastic model and a generalized Norton viscoplastic model were used to account for the time-dependent behavior of TP-based composite laminates, which are exacerbated at high temperature. To precisely evaluate the fracture parameters (e.g. R-curves) in TP composites, a study on the mesh type and its refinement was carried out. Using the finite element code Cast3m, the G θ method was applied in order to test its capability to determine the mode I strain Energy Release Rate for different testing conditions. (5)-Harness satin weave carbon fabric reinforced PolyPhenylene Sulfide (5HS C/PPS) laminates have been studied with two different stacking sequences: a Quasi-Isotropic (QI) sequence characterized by a fibre-dominated behaviour and an Angle-Ply (AP) sequence whose behaviour is matrix-dominated. Tensile tests have been simulated on Single-Edge-Notch (SEN) specimens (with different notch lengths) subjected to quasi-static loadings in order to investigate the effect of time-dependent behaviors on translaminar failure and strain Energy Release Rate. The R-curves have been derived from the computation of the strain Energy Release Rate and the corresponding crack length. Ultimately, it is possible to build R-curves based on the evaluation of fracture toughness for different ratios a/w and to compare these curves to the ones obtained from experiments.
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influence of matrix ductility and toughness on strain Energy Release Rate and failure behavior of woven ply reinforced thermoplastic structures at high temperature
Composites Part B-engineering, 2018Co-Authors: B Vieille, M Chabchoub, Christophe GautreletAbstract:Abstract The purpose of the present work is to investigate damage evolution in 5-harness satin weave carbon fabric reinforced PolyPhenylene Sulphide (PPS) structures with an initial edge notch. To understand how the physical properties of the constituents (e.g. matrix toughness and ductility) and the architecture of reinforcement (woven-ply) affect the fracture behavior of C/PPS laminates, it is useful to have analytical representation of the translaminar failure modes based on fracture mechanics concepts, the strain Energy Release Rate G especially. Translaminar failure is determined by the combination of loading, location of defect and material heterogeneity (presence of matrix-rich regions at the crimp area in woven-ply laminates). When translaminar failure is initiated from an existing notch, a sequence of Energy-absorbing events (fiber breakage, matrix cracking, fibers pull-out, fiber/matrix debonding) occurs in a region surrounding the notch tip. The knowledge of Energy-absorbing processes is therefore important since they are responsible for the toughness of the composite. Depending on laminates' stacking sequence, the contribution of matrix behavior to strain Energy Release Rate can be evaluated during damage in both brittle and ductile composite laminates subjected to high temperature conditions (T > T g ) when matrix ductility and toughness are enhanced. Depending on the initial notch orientation (0 or 45°), the failure mode is either a mode I or a mixed mode (I + II). The acoustic Energy associated with translaminar failure was correlated with the strain Energy Release Rate during translaminar failure. The total strain Energy Release Rate in quasi-isotropic (QI) laminates is 6 times as low as in angle-ply (AP) laminates, suggesting that large plastic deformation (due to a matrix-driven behavior and an enhanced matrix ductility at T > Tg) are instrumental in dissipating a great portion of the mechanical Energy brought to the specimen in AP laminates. The “material” effect is combined with a structural one (rotation of the fibers) at the crack tip, and leads to ductile failure. Both effects contribute to high fracture toughness in AP laminates.
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influence of stress concentration factor on the evolution of the strain Energy Release Rate at high temperature in highly ductile carbon fibers reinforced thermoplastic structures
International Conference Design and Modeling of Mechanical Systems, 2017Co-Authors: M Chabchoub, B Vieille, Christophe Gautrelet, Moez Beyaoui, M Taktak, M Haddar, Lakhdar TalebAbstract:This work was aimed at investigating the influence of stress concentration factor on the evolution of the strain Energy Release Rate J in 5-harness satin weave carbon fabrics reinforced Polyphenylene sulphide (PPS) structures at 120 °C (higher than the transition temperature Tg). The studied angle-ply (AP) laminates are characterized by a highly ductile behavior. For this purpose, the load separation method, as well as the compliance method, are applied in order to determine the strain Energy Release Rate J for different crack length over specimen width ratios a/W. A fractographic analysis was conducted to understand the chronology of damage mechanisms which significantly depends on the enhanced PPS matrix ductility and toughness at T > Tg. An acoustic emission (AE) technique was used to investigate the correlation between the Energy Released during translaminar cracking and the cumulative AE Energy/events for different stress concentration factors. Fibers breakage appears to be not very energetic from the AE standpoint. Finally, blunting is instrumental in increasing the strain Energy Release Rate in specimens with low-stress concentration factors, due to large plastic deformations at the crack tip.
Janis Varna - One of the best experts on this subject based on the ideXlab platform.
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steady state Energy Release Rate for fiber matrix interface debond growth in unidirectional composites
International Journal of Damage Mechanics, 2017Co-Authors: Andrejs Pupurs, Janis VarnaAbstract:Analytical closed form solution is derived for Energy Release Rate due to steady-state debond growth along a broken fiber in unidirectional composite. The problem is represented by a three concentric cylinder model, where the broken and partially debonded fiber is embedded in resin and this unit is surrounded by homogenized effective composite. Parametric analysis shows that parameters in the very simple quadratic expression for Energy Release Rate dependence on temperature change and mechanical strain are rather insensitive with respect to changes in constituent elastic properties and fiber content. The importance to have a large outer radius of the effective composite phase in the concentric cylinder model is demonstRated.
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Energy Release Rate based fiber matrix debond growth in fatigue part i self similar crack growth
Mechanics of Advanced Materials and Structures, 2013Co-Authors: Andrejs Pupurs, Janis VarnaAbstract:The strain Energy Release Rate related to debond crack growth along the fiber/matrix interface in a unidirectional (UD) composite with a broken fiber is analyzed. The UD composite is represented by a model with axial symmetry consisting of three concentric cylinders: broken and partially debonded fiber in the middle surrounded by matrix, which is embedded in a large block of effective composite. Analytical solution for Mode II Energy Release Rate is found and parametric analysis performed in the self-similar debond crack propagation region. It is shown that many anisotropic elastic constants of the fiber, which are usually not known, have a small effect on .
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Energy Release Rate based fiber matrix debond growth in fatigue part i self similar crack growth
Mechanics of Advanced Materials and Structures, 2013Co-Authors: Andrejs Pupurs, Janis VarnaAbstract:The strain Energy Release Rate related to debond crack growth along the fiber/matrix interface in a unidirectional (UD) composite with a broken fiber is analyzed. The UD composite is represented by...
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Energy Release Rate based fiber matrix debond growth in fatigue part ii debond growth analysis using paris law
Mechanics of Advanced Materials and Structures, 2013Co-Authors: Andrejs Pupurs, A Krasnikovs, Janis VarnaAbstract:The strain Energy Release Rate related to debond crack growth along the fiber/matrix interface in a unidirectional composite with a broken and partially debonded fiber is analyzed. The focus of this article (Part II) in contrast to the self-similar crack growth analysis in Part I [1] is on the growth of short debonds near the fiber break. Since the self-similarity condition is not valid for interactive cracks, numerical FEM simulations were used to calculate magnification of previously described coefficients in the strain Energy Release Rate expression. The findings from these studies are used in simulation of the debond growth in tension-tension fatigue using Paris law.
Christophe Gautrelet - One of the best experts on this subject based on the ideXlab platform.
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influence of matrix ductility and toughness on strain Energy Release Rate and failure behavior of woven ply reinforced thermoplastic structures at high temperature
Composites Part B-engineering, 2018Co-Authors: B Vieille, M Chabchoub, Christophe GautreletAbstract:Abstract The purpose of the present work is to investigate damage evolution in 5-harness satin weave carbon fabric reinforced PolyPhenylene Sulphide (PPS) structures with an initial edge notch. To understand how the physical properties of the constituents (e.g. matrix toughness and ductility) and the architecture of reinforcement (woven-ply) affect the fracture behavior of C/PPS laminates, it is useful to have analytical representation of the translaminar failure modes based on fracture mechanics concepts, the strain Energy Release Rate G especially. Translaminar failure is determined by the combination of loading, location of defect and material heterogeneity (presence of matrix-rich regions at the crimp area in woven-ply laminates). When translaminar failure is initiated from an existing notch, a sequence of Energy-absorbing events (fiber breakage, matrix cracking, fibers pull-out, fiber/matrix debonding) occurs in a region surrounding the notch tip. The knowledge of Energy-absorbing processes is therefore important since they are responsible for the toughness of the composite. Depending on laminates' stacking sequence, the contribution of matrix behavior to strain Energy Release Rate can be evaluated during damage in both brittle and ductile composite laminates subjected to high temperature conditions (T > T g ) when matrix ductility and toughness are enhanced. Depending on the initial notch orientation (0 or 45°), the failure mode is either a mode I or a mixed mode (I + II). The acoustic Energy associated with translaminar failure was correlated with the strain Energy Release Rate during translaminar failure. The total strain Energy Release Rate in quasi-isotropic (QI) laminates is 6 times as low as in angle-ply (AP) laminates, suggesting that large plastic deformation (due to a matrix-driven behavior and an enhanced matrix ductility at T > Tg) are instrumental in dissipating a great portion of the mechanical Energy brought to the specimen in AP laminates. The “material” effect is combined with a structural one (rotation of the fibers) at the crack tip, and leads to ductile failure. Both effects contribute to high fracture toughness in AP laminates.
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influence of stress concentration factor on the evolution of the strain Energy Release Rate at high temperature in highly ductile carbon fibers reinforced thermoplastic structures
International Conference Design and Modeling of Mechanical Systems, 2017Co-Authors: M Chabchoub, B Vieille, Christophe Gautrelet, Moez Beyaoui, M Taktak, M Haddar, Lakhdar TalebAbstract:This work was aimed at investigating the influence of stress concentration factor on the evolution of the strain Energy Release Rate J in 5-harness satin weave carbon fabrics reinforced Polyphenylene sulphide (PPS) structures at 120 °C (higher than the transition temperature Tg). The studied angle-ply (AP) laminates are characterized by a highly ductile behavior. For this purpose, the load separation method, as well as the compliance method, are applied in order to determine the strain Energy Release Rate J for different crack length over specimen width ratios a/W. A fractographic analysis was conducted to understand the chronology of damage mechanisms which significantly depends on the enhanced PPS matrix ductility and toughness at T > Tg. An acoustic emission (AE) technique was used to investigate the correlation between the Energy Released during translaminar cracking and the cumulative AE Energy/events for different stress concentration factors. Fibers breakage appears to be not very energetic from the AE standpoint. Finally, blunting is instrumental in increasing the strain Energy Release Rate in specimens with low-stress concentration factors, due to large plastic deformations at the crack tip.
B Vieille - One of the best experts on this subject based on the ideXlab platform.
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Numerical estimation of the mode I strain Energy Release Rate in woven-ply thermoplastic-based composites at high temperature based on Gθ method
Theoretical and Applied Fracture Mechanics, 2019Co-Authors: M Chabchoub, B Vieille, Rostand Moutou PittiAbstract:The present work was aimed at estimating the mode I strain Energy Release Rate at crack initiation in woven-ply thermoplastic (TP) based laminates at high temperature T>T g . A linear spectral viscoelastic model and a generalized Norton viscoplastic model were used to account for the time-dependent behavior of TP-based composite laminates, which are exacerbated at high temperature. To precisely evaluate the fracture parameters (e.g. R-curves) in TP composites, a study on the mesh type and its refinement was carried out. Using the finite element code Cast3m, the G θ method was applied in order to test its capability to determine the mode I strain Energy Release Rate for different testing conditions. (5)-Harness satin weave carbon fabric reinforced PolyPhenylene Sulfide (5HS C/PPS) laminates have been studied with two different stacking sequences: a Quasi-Isotropic (QI) sequence characterized by a fibre-dominated behaviour and an Angle-Ply (AP) sequence whose behaviour is matrix-dominated. Tensile tests have been simulated on Single-Edge-Notch (SEN) specimens (with different notch lengths) subjected to quasi-static loadings in order to investigate the effect of time-dependent behaviors on translaminar failure and strain Energy Release Rate. The R-curves have been derived from the computation of the strain Energy Release Rate and the corresponding crack length. Ultimately, it is possible to build R-curves based on the evaluation of fracture toughness for different ratios a/w and to compare these curves to the ones obtained from experiments.
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influence of matrix ductility and toughness on strain Energy Release Rate and failure behavior of woven ply reinforced thermoplastic structures at high temperature
Composites Part B-engineering, 2018Co-Authors: B Vieille, M Chabchoub, Christophe GautreletAbstract:Abstract The purpose of the present work is to investigate damage evolution in 5-harness satin weave carbon fabric reinforced PolyPhenylene Sulphide (PPS) structures with an initial edge notch. To understand how the physical properties of the constituents (e.g. matrix toughness and ductility) and the architecture of reinforcement (woven-ply) affect the fracture behavior of C/PPS laminates, it is useful to have analytical representation of the translaminar failure modes based on fracture mechanics concepts, the strain Energy Release Rate G especially. Translaminar failure is determined by the combination of loading, location of defect and material heterogeneity (presence of matrix-rich regions at the crimp area in woven-ply laminates). When translaminar failure is initiated from an existing notch, a sequence of Energy-absorbing events (fiber breakage, matrix cracking, fibers pull-out, fiber/matrix debonding) occurs in a region surrounding the notch tip. The knowledge of Energy-absorbing processes is therefore important since they are responsible for the toughness of the composite. Depending on laminates' stacking sequence, the contribution of matrix behavior to strain Energy Release Rate can be evaluated during damage in both brittle and ductile composite laminates subjected to high temperature conditions (T > T g ) when matrix ductility and toughness are enhanced. Depending on the initial notch orientation (0 or 45°), the failure mode is either a mode I or a mixed mode (I + II). The acoustic Energy associated with translaminar failure was correlated with the strain Energy Release Rate during translaminar failure. The total strain Energy Release Rate in quasi-isotropic (QI) laminates is 6 times as low as in angle-ply (AP) laminates, suggesting that large plastic deformation (due to a matrix-driven behavior and an enhanced matrix ductility at T > Tg) are instrumental in dissipating a great portion of the mechanical Energy brought to the specimen in AP laminates. The “material” effect is combined with a structural one (rotation of the fibers) at the crack tip, and leads to ductile failure. Both effects contribute to high fracture toughness in AP laminates.
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influence of stress concentration factor on the evolution of the strain Energy Release Rate at high temperature in highly ductile carbon fibers reinforced thermoplastic structures
International Conference Design and Modeling of Mechanical Systems, 2017Co-Authors: M Chabchoub, B Vieille, Christophe Gautrelet, Moez Beyaoui, M Taktak, M Haddar, Lakhdar TalebAbstract:This work was aimed at investigating the influence of stress concentration factor on the evolution of the strain Energy Release Rate J in 5-harness satin weave carbon fabrics reinforced Polyphenylene sulphide (PPS) structures at 120 °C (higher than the transition temperature Tg). The studied angle-ply (AP) laminates are characterized by a highly ductile behavior. For this purpose, the load separation method, as well as the compliance method, are applied in order to determine the strain Energy Release Rate J for different crack length over specimen width ratios a/W. A fractographic analysis was conducted to understand the chronology of damage mechanisms which significantly depends on the enhanced PPS matrix ductility and toughness at T > Tg. An acoustic emission (AE) technique was used to investigate the correlation between the Energy Released during translaminar cracking and the cumulative AE Energy/events for different stress concentration factors. Fibers breakage appears to be not very energetic from the AE standpoint. Finally, blunting is instrumental in increasing the strain Energy Release Rate in specimens with low-stress concentration factors, due to large plastic deformations at the crack tip.