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Vladislav Mantic - One of the best experts on this subject based on the ideXlab platform.
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A linear elastic-brittle Interface model: application for the onset and propagation of a fibre-Matrix Interface crack under biaxial transverse loads
International Journal of Fracture, 2015Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:A new linear elastic and perfectly brittle Interface model for mixed mode is presented and analysed. In this model, the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential initially-linear-elastic springs takes into account possible frictionless elastic contact between adherents once a portion of the Interface is broken. A perfectly brittle failure criterion is employed for the springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. A unified way to represent several phenomenological both energy and stress based failure criteria is introduced. A proof relating the energy release rate and tractions at an Interface point (not necessarily a crack tip point) is introduced for this Interface model by adapting Irwin’s crack closure technique for the first time. The main advantages of the present Interface model are its simplicity, robustness and computational efficiency, even in the presence of snap-back and snap-through instabilities, when the so-called sequentially linear (elastic) analysis is applied. This model is applied here in order to study crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads. Firstly, this model is used to obtain analytical predictions about Interface crack onset, while investigating a single fibre embedded in a Matrix which is subjected to uniform remote transverse loads. Then, numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure is initiated by the onset of a finite debond in the neighbourhood of the Interface point where the failure criterion is first reached (under increasing proportional load); this debond further propagates along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for several parametric studies of the influence of load biaxiality, fracture-mode sensitivity and brittleness number, and for checking the computational procedure implemented.
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application of a linear elastic brittle Interface model to the crack initiation and propagation at fibre Matrix Interface under biaxial transverse loads
arXiv: Computational Physics, 2013Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:The crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads is studied by a new linear elastic - (perfectly) brittle Interface model. In this model the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential of initially linear elastic springs takes into account possible frictionless elastic contact between fibre and Matrix once a portion of the Interface is broken. A brittle failure criterion is employed for the distribution of springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. The main advantages of the present Interface model are its simplicity, robustness and its computational efficiency when the so-called sequentially linear analysis is applied. Moreover, in the present plane strain problem of a single fibre embedded in a Matrix subjected to uniform remote transverse loads, this model can be used to obtain analytic predictions of Interface crack onset. The numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure initiates by onset of a finite debond in the neighbourhood of an Interface point where the failure criterion is reached first (under increasing proportional load), this debond further propagating along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for checking the computational procedure implemented, an excellent agreement being obtained.
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crack onset and growth at the fibre Matrix Interface under a remote biaxial transverse load application of a coupled stress and energy criterion
International Journal of Solids and Structures, 2012Co-Authors: Vladislav Mantic, I G GarciaAbstract:Abstract A theoretical model for prediction of the critical load generating a crack onset at the fibre–Matrix Interface under a remote biaxial transverse load is presented. In particular, this work is focused on the tension dominated failure. After an abrupt onset the crack grows unstably up to achieving an arrest length. A simple plane strain model of a single circular inclusion surrounded by an unbounded Matrix allows obtaining conclusions approximately valid for a dilute fibre packing. Linear isotropic elastic behaviour is assumed for both inclusion and Matrix. Two classical elastic solutions for both perfectly bonded and partially debonded circular inclusions are used together with a coupled stress and energy criterion, proposed recently in the framework of finite fracture mechanics, and a phenomenological law for fracture toughness of Interface cracks growing in fracture mixed mode. The obtained analytical and semi-analytical expressions make easy studying the influence of all the dimensionless parameters governing the fibre–Matrix system behaviour: Dundurs elastic bimaterial constants α and β , the Interface brittleness number γ and the load biaxiality parameter η . A size effect of the inclusion radius on the critical load is predicted, smaller inclusions being stronger and less dependent on the secondary load. Finally, an experimental procedure for measurement of the fibre–Matrix Interface fracture and strength properties is proposed.
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bem analysis of crack onset and propagation along fiber Matrix Interface under transverse tension using a linear elastic brittle Interface model
Engineering Analysis With Boundary Elements, 2011Co-Authors: L Tavara, Vladislav Mantic, Enrique Graciani, F ParisAbstract:The behavior of the fiber–Matrix Interface under transverse tension is studied by means of a new linear elastic–brittle Interface model. Similar models, also called weak or imperfect Interface models, are frequently applied to describe the behavior of adhesively bonded joints. The Interface is modeled by a continuous distribution of linear-elastic springs which simulates the presence of a thin adhesive layer (interphase). In the present work a new linear elastic–brittle constitutive law for the continuous distribution of springs is introduced. In this law the normal and tangential stresses across the undamaged Interface are, respectively, proportional to the relative normal and tangential displacements. This model not only allows for the study of crack growth but also for the study of crack onset. An important feature of this law is that it takes into account the variation of the fracture toughness with the fracture mode mixity of a crack growing along the Interface between bonded solids, in agreement with previous experimental results. The present linear elastic–brittle Interface model is implemented in a 2D boundary element method (BEM) code to carry out micromechanical analysis of the fiber–Matrix Interface failure in fiber-reinforced composite materials. It is considered that the behavior of the fiber–Matrix interphase can be modeled by the present model although, strictly speaking, there is usually no intermediate material between fiber and Matrix. A linear-elastic isotropic behavior of both fiber and Matrix is assumed, the fiber being stiffer than the Matrix. The failure mechanism of an isolated fiber under transverse tension, i.e., the onset and growth of the fiber–Matrix Interface crack, is studied. The present model shows that failure along the Interface initiates with an abrupt onset of a partial debonding between the fiber and the Matrix, caused by presence of the maximum radial stress at the Interface, and this debonding further develops as a crack growing along the Interface.
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numerical characterisation of the fibre Matrix Interface crack growth in composites under transverse compression
Engineering Fracture Mechanics, 2008Co-Authors: E Correa, Vladislav Mantic, F ParisAbstract:Abstract Inter-fibre failure under compression transverse to the fibres is studied at micromechanical level. Interfacial fracture mechanics concepts, associated to both the open model and the contact model, are applied. A numerical study is performed using the boundary element method aimed at explaining the origin and evolution of the damage at micromechanical level, considered as fibre–Matrix Interface cracks. Assuming that the damage starts as small debonds originated by shear stresses at the position where their maximum values are reached, it has been found that the crack shows different morphologies at both tips: an open one and a closed one with a large contact zone. Then the Interface crack grows unstably in mixed mode only on the open tip side until this growth changes to stable, once the crack closes at this tip, with the generation of a contact zone.
L Tavara - One of the best experts on this subject based on the ideXlab platform.
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A linear elastic-brittle Interface model: application for the onset and propagation of a fibre-Matrix Interface crack under biaxial transverse loads
International Journal of Fracture, 2015Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:A new linear elastic and perfectly brittle Interface model for mixed mode is presented and analysed. In this model, the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential initially-linear-elastic springs takes into account possible frictionless elastic contact between adherents once a portion of the Interface is broken. A perfectly brittle failure criterion is employed for the springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. A unified way to represent several phenomenological both energy and stress based failure criteria is introduced. A proof relating the energy release rate and tractions at an Interface point (not necessarily a crack tip point) is introduced for this Interface model by adapting Irwin’s crack closure technique for the first time. The main advantages of the present Interface model are its simplicity, robustness and computational efficiency, even in the presence of snap-back and snap-through instabilities, when the so-called sequentially linear (elastic) analysis is applied. This model is applied here in order to study crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads. Firstly, this model is used to obtain analytical predictions about Interface crack onset, while investigating a single fibre embedded in a Matrix which is subjected to uniform remote transverse loads. Then, numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure is initiated by the onset of a finite debond in the neighbourhood of the Interface point where the failure criterion is first reached (under increasing proportional load); this debond further propagates along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for several parametric studies of the influence of load biaxiality, fracture-mode sensitivity and brittleness number, and for checking the computational procedure implemented.
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application of a linear elastic brittle Interface model to the crack initiation and propagation at fibre Matrix Interface under biaxial transverse loads
arXiv: Computational Physics, 2013Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:The crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads is studied by a new linear elastic - (perfectly) brittle Interface model. In this model the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential of initially linear elastic springs takes into account possible frictionless elastic contact between fibre and Matrix once a portion of the Interface is broken. A brittle failure criterion is employed for the distribution of springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. The main advantages of the present Interface model are its simplicity, robustness and its computational efficiency when the so-called sequentially linear analysis is applied. Moreover, in the present plane strain problem of a single fibre embedded in a Matrix subjected to uniform remote transverse loads, this model can be used to obtain analytic predictions of Interface crack onset. The numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure initiates by onset of a finite debond in the neighbourhood of an Interface point where the failure criterion is reached first (under increasing proportional load), this debond further propagating along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for checking the computational procedure implemented, an excellent agreement being obtained.
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bem analysis of crack onset and propagation along fiber Matrix Interface under transverse tension using a linear elastic brittle Interface model
Engineering Analysis With Boundary Elements, 2011Co-Authors: L Tavara, Vladislav Mantic, Enrique Graciani, F ParisAbstract:The behavior of the fiber–Matrix Interface under transverse tension is studied by means of a new linear elastic–brittle Interface model. Similar models, also called weak or imperfect Interface models, are frequently applied to describe the behavior of adhesively bonded joints. The Interface is modeled by a continuous distribution of linear-elastic springs which simulates the presence of a thin adhesive layer (interphase). In the present work a new linear elastic–brittle constitutive law for the continuous distribution of springs is introduced. In this law the normal and tangential stresses across the undamaged Interface are, respectively, proportional to the relative normal and tangential displacements. This model not only allows for the study of crack growth but also for the study of crack onset. An important feature of this law is that it takes into account the variation of the fracture toughness with the fracture mode mixity of a crack growing along the Interface between bonded solids, in agreement with previous experimental results. The present linear elastic–brittle Interface model is implemented in a 2D boundary element method (BEM) code to carry out micromechanical analysis of the fiber–Matrix Interface failure in fiber-reinforced composite materials. It is considered that the behavior of the fiber–Matrix interphase can be modeled by the present model although, strictly speaking, there is usually no intermediate material between fiber and Matrix. A linear-elastic isotropic behavior of both fiber and Matrix is assumed, the fiber being stiffer than the Matrix. The failure mechanism of an isolated fiber under transverse tension, i.e., the onset and growth of the fiber–Matrix Interface crack, is studied. The present model shows that failure along the Interface initiates with an abrupt onset of a partial debonding between the fiber and the Matrix, caused by presence of the maximum radial stress at the Interface, and this debonding further develops as a crack growing along the Interface.
F Paris - One of the best experts on this subject based on the ideXlab platform.
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bem analysis of crack onset and propagation along fiber Matrix Interface under transverse tension using a linear elastic brittle Interface model
Engineering Analysis With Boundary Elements, 2011Co-Authors: L Tavara, Vladislav Mantic, Enrique Graciani, F ParisAbstract:The behavior of the fiber–Matrix Interface under transverse tension is studied by means of a new linear elastic–brittle Interface model. Similar models, also called weak or imperfect Interface models, are frequently applied to describe the behavior of adhesively bonded joints. The Interface is modeled by a continuous distribution of linear-elastic springs which simulates the presence of a thin adhesive layer (interphase). In the present work a new linear elastic–brittle constitutive law for the continuous distribution of springs is introduced. In this law the normal and tangential stresses across the undamaged Interface are, respectively, proportional to the relative normal and tangential displacements. This model not only allows for the study of crack growth but also for the study of crack onset. An important feature of this law is that it takes into account the variation of the fracture toughness with the fracture mode mixity of a crack growing along the Interface between bonded solids, in agreement with previous experimental results. The present linear elastic–brittle Interface model is implemented in a 2D boundary element method (BEM) code to carry out micromechanical analysis of the fiber–Matrix Interface failure in fiber-reinforced composite materials. It is considered that the behavior of the fiber–Matrix interphase can be modeled by the present model although, strictly speaking, there is usually no intermediate material between fiber and Matrix. A linear-elastic isotropic behavior of both fiber and Matrix is assumed, the fiber being stiffer than the Matrix. The failure mechanism of an isolated fiber under transverse tension, i.e., the onset and growth of the fiber–Matrix Interface crack, is studied. The present model shows that failure along the Interface initiates with an abrupt onset of a partial debonding between the fiber and the Matrix, caused by presence of the maximum radial stress at the Interface, and this debonding further develops as a crack growing along the Interface.
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numerical characterisation of the fibre Matrix Interface crack growth in composites under transverse compression
Engineering Fracture Mechanics, 2008Co-Authors: E Correa, Vladislav Mantic, F ParisAbstract:Abstract Inter-fibre failure under compression transverse to the fibres is studied at micromechanical level. Interfacial fracture mechanics concepts, associated to both the open model and the contact model, are applied. A numerical study is performed using the boundary element method aimed at explaining the origin and evolution of the damage at micromechanical level, considered as fibre–Matrix Interface cracks. Assuming that the damage starts as small debonds originated by shear stresses at the position where their maximum values are reached, it has been found that the crack shows different morphologies at both tips: an open one and a closed one with a large contact zone. Then the Interface crack grows unstably in mixed mode only on the open tip side until this growth changes to stable, once the crack closes at this tip, with the generation of a contact zone.
Enrique Graciani - One of the best experts on this subject based on the ideXlab platform.
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A linear elastic-brittle Interface model: application for the onset and propagation of a fibre-Matrix Interface crack under biaxial transverse loads
International Journal of Fracture, 2015Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:A new linear elastic and perfectly brittle Interface model for mixed mode is presented and analysed. In this model, the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential initially-linear-elastic springs takes into account possible frictionless elastic contact between adherents once a portion of the Interface is broken. A perfectly brittle failure criterion is employed for the springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. A unified way to represent several phenomenological both energy and stress based failure criteria is introduced. A proof relating the energy release rate and tractions at an Interface point (not necessarily a crack tip point) is introduced for this Interface model by adapting Irwin’s crack closure technique for the first time. The main advantages of the present Interface model are its simplicity, robustness and computational efficiency, even in the presence of snap-back and snap-through instabilities, when the so-called sequentially linear (elastic) analysis is applied. This model is applied here in order to study crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads. Firstly, this model is used to obtain analytical predictions about Interface crack onset, while investigating a single fibre embedded in a Matrix which is subjected to uniform remote transverse loads. Then, numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure is initiated by the onset of a finite debond in the neighbourhood of the Interface point where the failure criterion is first reached (under increasing proportional load); this debond further propagates along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for several parametric studies of the influence of load biaxiality, fracture-mode sensitivity and brittleness number, and for checking the computational procedure implemented.
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application of a linear elastic brittle Interface model to the crack initiation and propagation at fibre Matrix Interface under biaxial transverse loads
arXiv: Computational Physics, 2013Co-Authors: Vladislav Mantic, L Tavara, Enrique Graciani, A Blazquez, F ParisAbstract:The crack onset and propagation at the fibre-Matrix Interface in a composite under tensile/compressive remote biaxial transverse loads is studied by a new linear elastic - (perfectly) brittle Interface model. In this model the Interface is represented by a continuous distribution of springs which simulates the presence of a thin elastic layer. The constitutive law for the continuous distribution of normal and tangential of initially linear elastic springs takes into account possible frictionless elastic contact between fibre and Matrix once a portion of the Interface is broken. A brittle failure criterion is employed for the distribution of springs, which enables the study of crack onset and propagation. This Interface failure criterion takes into account the variation of the Interface fracture toughness with the fracture mode mixity. The main advantages of the present Interface model are its simplicity, robustness and its computational efficiency when the so-called sequentially linear analysis is applied. Moreover, in the present plane strain problem of a single fibre embedded in a Matrix subjected to uniform remote transverse loads, this model can be used to obtain analytic predictions of Interface crack onset. The numerical results provided by a 2D boundary element analysis show that a fibre-Matrix Interface failure initiates by onset of a finite debond in the neighbourhood of an Interface point where the failure criterion is reached first (under increasing proportional load), this debond further propagating along the Interface in mixed mode or even, in some configurations, with the crack tip under compression. The analytical predictions of the debond onset position and associated critical load are used for checking the computational procedure implemented, an excellent agreement being obtained.
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bem analysis of crack onset and propagation along fiber Matrix Interface under transverse tension using a linear elastic brittle Interface model
Engineering Analysis With Boundary Elements, 2011Co-Authors: L Tavara, Vladislav Mantic, Enrique Graciani, F ParisAbstract:The behavior of the fiber–Matrix Interface under transverse tension is studied by means of a new linear elastic–brittle Interface model. Similar models, also called weak or imperfect Interface models, are frequently applied to describe the behavior of adhesively bonded joints. The Interface is modeled by a continuous distribution of linear-elastic springs which simulates the presence of a thin adhesive layer (interphase). In the present work a new linear elastic–brittle constitutive law for the continuous distribution of springs is introduced. In this law the normal and tangential stresses across the undamaged Interface are, respectively, proportional to the relative normal and tangential displacements. This model not only allows for the study of crack growth but also for the study of crack onset. An important feature of this law is that it takes into account the variation of the fracture toughness with the fracture mode mixity of a crack growing along the Interface between bonded solids, in agreement with previous experimental results. The present linear elastic–brittle Interface model is implemented in a 2D boundary element method (BEM) code to carry out micromechanical analysis of the fiber–Matrix Interface failure in fiber-reinforced composite materials. It is considered that the behavior of the fiber–Matrix interphase can be modeled by the present model although, strictly speaking, there is usually no intermediate material between fiber and Matrix. A linear-elastic isotropic behavior of both fiber and Matrix is assumed, the fiber being stiffer than the Matrix. The failure mechanism of an isolated fiber under transverse tension, i.e., the onset and growth of the fiber–Matrix Interface crack, is studied. The present model shows that failure along the Interface initiates with an abrupt onset of a partial debonding between the fiber and the Matrix, caused by presence of the maximum radial stress at the Interface, and this debonding further develops as a crack growing along the Interface.
Michael A Slivka - One of the best experts on this subject based on the ideXlab platform.
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fiber Matrix Interface studies on bioabsorbable composite materials for internal fixation of bone fractures ii a new method using laser scanning confocal microscopy
Journal of Biomedical Materials Research, 1997Co-Authors: Michael A Slivka, Chihchang ChuAbstract:In this study, a new visual characterization method was developed using laser scanning confocal microscopy (LSCM) to study morphologic properties, particularly at the fiber-Matrix Interface, by optical sectioning of bioabsorbable single-fiber composites. The Interface gap width (IGW) between the fiber and Matrix, and the changes in IGW after in vitro hydrolysis, named the gap rate (Rg), were measured from images obtained using the LSCM. Higher values for IGW and Rg showed faster degradation of the fiber-Matrix Interface. These parameters were used to investigate the effects of strain, wicking, different reinforcing fibers, and γ-irradiation on the fiber-Matrix Interface morphology. The component materials used were nonbioabsorbable AS4 carbon (C) fibers, bioabsorbable calcium phosphate (CaP), poly(glycolic acid) (PGA), and chitin fibers, and bioabsorbable poly(L-lactic acid) (PLLA) Matrix. The application of strain on CaP/PLLA composites increased the IGW up to about 15%, after which there was no change up to 25%. The Rg for CaP/PLLA composites with the fiber ends exposed in vitro (permitting wicking) was greater than for CaP/PLLA with the fiber ends embedded completely within the Matrix (preventing wicking). Open-end C/PLLA composites had the slowest rate of Interface degradation in vitro, followed by chitin/PLLA, PGA/PLLA, and CaP/PLLA. The exposure of closed-end CaP/PLLA composites to 4 Mrad of γ-irradiation, in air at room temperature or in vacuum at 77K, accelerated the rate of Interface degradation in vitro. In conclusion, an effective new visual characterization method was developed using LSCM, and it was used to show that (a) moderate strain could accelerate the degradation of the Interface, (b) fiber-Matrix Interface wicking could accelerate the rate of degradation of the Interface, (c) the rate of Interface degradation depends on the type of fiber used, and (d) γ-irradiation could accelerate the rate of Interface degradation. Furthermore, the results of LSCM analysis of different reinforcing fibers with a PLLA Matrix agree with measurements of interfacial shear strength (IFSS) and single-fiber tensile strength reported in Part I of this study. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 37, 353–362, 1997.
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fiber Matrix Interface studies on bioabsorbable composite materials for internal fixation of bone fractures i raw material evaluation and measurement of fiber Matrix interfacial adhesion
Journal of Biomedical Materials Research, 1997Co-Authors: Michael A Slivka, Chihchang Chu, Ida A AdisaputroAbstract:The objective of this study was to characterize and evaluate the performance of various fiber-Matrix composite systems by studying the mechanical, thermal, and physical properties of the fiber and Matrix components, and by studying the fiber-Matrix Interface adhesion strength using both microbond and fragmentation methods. The composites studied were poly(L-lactic acid) (PLLA) Matrix reinforced with continuous fibers of either nonabsorbable AS4 carbon (C), absorbable calcium phosphate (CaP), poly(glycolic acid) (PGA), or chitin. Carbon and CaP single fibers had high Young's moduli and failed in a brittle manner. PGA and chitin single fibers had relatively lower Young's moduli and relatively higher ductility. Upon in vitro hydrolysis, CaP fibers retained 17% of their tensile strength and 39% of their Young's modulus after 12 h, PGA fibers retained 10% of their tensile strength and 52% of their Young's modulus after 16 days, and chitin fibers retained 87% of their tensile strength and 130% of their Young's modulus after 25 days. PLLA films had much lower strength and Young's moduli, but much higher ductility relative to the single fibers. Using the microbond method, the initial fiber-Matrix interfacial shear strength (IFSS) of C/PLLA and CaP/PLLA microcomposites was 33.9 and 12.6 MPa, respectively. Upon in vitro hydrolysis, C/PLLA retained 49% of IFSS after 15 days and CaP/PLLA retained 46% of IFSS after 6 h. Using a fiber fragmentation method, the initial IFSS of C/PLLA, CaP/PLLA, and chitin/PLLA was 22.2, 15.6, and 28.3 MPa, respectively. The performance of carbon fibers and C/PLLA composites was superior to the other fibers and fiber/PLLA systems, but the carbon fiber was nonabsorbable. CaP had the most suitable modulus of the absorbable fibers for fixing cortical bone fractures, but its rapid deterioration of mechanical properties and loss of IFSS limits its use. PGA and chitin fibers had suitable mechanical properties and their retention for fixing cancellous bone fractures, but likely had insufficient stiffness for applications such as bone plates for fixing cortical bone fractures. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 36, 469–477, 1997.