The Experts below are selected from a list of 68427 Experts worldwide ranked by ideXlab platform
Vadim V. Silberschmidt - One of the best experts on this subject based on the ideXlab platform.
-
characterisation and numerical modelling of complex deformation Behaviour in thermally bonded nonwovens
Computational Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Baris Sabuncuoglu, Vadim V. SilberschmidtAbstract:A complex time-dependent deformation and Damage Behaviour in polymer-based nonwovens are analysed under conditions of multi-stage uniaxial loading. Elastic–plastic and viscous properties of a polypropylene-based fabric are obtained by series of tensile, creep and relaxation tests performed on single fibres extracted from the studied fabric. These properties are implemented in a finite-element (FE) model of nonwoven with direct introduction of fibres according to their actual orientation distribution in order to simulate the rate-dependent deformation up to the onset of Damage in thermally bonded nonwovens. The predictions of FE simulations are compared with the experimental data of multi-stage deformation tensile tests and a good agreement is obtained including the mechanisms of deformation. Due to direct modelling of fibres based on their actual orientation distribution and implementation of viscous properties, the model could be extended to other types of polymer-based random fibrous networks.
-
Meso-scale deformation and Damage in thermally bonded nonwovens
Journal of Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Vadim V. SilberschmidtAbstract:Thermal bonding is the fastest and the cheapest technique for manufacturing nonwovens. Understanding mechanical Behaviour of these materials, especially related to Damage, can aid in design of products containing nonwoven parts. A finite element (FE) model incorporating mechanical properties related to Damage such as maximum stress and strain at failure of fabric’s fibres would be a powerful design and optimisation tool. In this study, polypropylene-based thermally bonded nonwovens manufactured at optimal processing conditions were used as a model system. A Damage Behaviour of the nonwoven fabric is governed by its single-fibre properties, which are obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that a single bond point was attached at both ends of each fibre. Additionally, similar tests were performed on unprocessed fibres, which form the nonwoven. Those experiments not only provided insight into Damage mechanisms of fibres in thermally bonded nonwovens but also demonstrated a significant drop in magnitudes of failure stress and respective strain in fibres due to the bonding process. A novel technique was introduced in this study to develop Damage criteria based on the deformation and fracture Behaviour of a single fibre in a thermally bonded nonwoven fabric. The Damage Behaviour of a fibrous network within the thermally bonded fabric was simulated with a FE model consisting of a number of fibres attached to two neighbouring bond points. Additionally, various arrangements of fibres’ orientation and material properties were implemented in the model to analyse the respective effects.
Farukh Farukh - One of the best experts on this subject based on the ideXlab platform.
-
characterisation and numerical modelling of complex deformation Behaviour in thermally bonded nonwovens
Computational Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Baris Sabuncuoglu, Vadim V. SilberschmidtAbstract:A complex time-dependent deformation and Damage Behaviour in polymer-based nonwovens are analysed under conditions of multi-stage uniaxial loading. Elastic–plastic and viscous properties of a polypropylene-based fabric are obtained by series of tensile, creep and relaxation tests performed on single fibres extracted from the studied fabric. These properties are implemented in a finite-element (FE) model of nonwoven with direct introduction of fibres according to their actual orientation distribution in order to simulate the rate-dependent deformation up to the onset of Damage in thermally bonded nonwovens. The predictions of FE simulations are compared with the experimental data of multi-stage deformation tensile tests and a good agreement is obtained including the mechanisms of deformation. Due to direct modelling of fibres based on their actual orientation distribution and implementation of viscous properties, the model could be extended to other types of polymer-based random fibrous networks.
-
Meso-scale deformation and Damage in thermally bonded nonwovens
Journal of Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Vadim V. SilberschmidtAbstract:Thermal bonding is the fastest and the cheapest technique for manufacturing nonwovens. Understanding mechanical Behaviour of these materials, especially related to Damage, can aid in design of products containing nonwoven parts. A finite element (FE) model incorporating mechanical properties related to Damage such as maximum stress and strain at failure of fabric’s fibres would be a powerful design and optimisation tool. In this study, polypropylene-based thermally bonded nonwovens manufactured at optimal processing conditions were used as a model system. A Damage Behaviour of the nonwoven fabric is governed by its single-fibre properties, which are obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that a single bond point was attached at both ends of each fibre. Additionally, similar tests were performed on unprocessed fibres, which form the nonwoven. Those experiments not only provided insight into Damage mechanisms of fibres in thermally bonded nonwovens but also demonstrated a significant drop in magnitudes of failure stress and respective strain in fibres due to the bonding process. A novel technique was introduced in this study to develop Damage criteria based on the deformation and fracture Behaviour of a single fibre in a thermally bonded nonwoven fabric. The Damage Behaviour of a fibrous network within the thermally bonded fabric was simulated with a FE model consisting of a number of fibres attached to two neighbouring bond points. Additionally, various arrangements of fibres’ orientation and material properties were implemented in the model to analyse the respective effects.
Juan Jose Lopezcela - One of the best experts on this subject based on the ideXlab platform.
-
effect of thermal ageing on the impact and flexural Damage Behaviour of carbon fibre reinforced epoxy laminates
Polymers, 2019Co-Authors: I Garciamoreno, M A Caminero, G P Rodriguez, Juan Jose LopezcelaAbstract:Most of the composite materials that are used in aerospace structures have been manufactured using a thermostable matrix, as epoxy resin. The region of stability of these polymers is defined by the glass transition temperature (Tg). However, operating temperatures close and above the Tg can cause a variation in the properties of the polymer and consequently, modify the mechanical properties of the composite material. Therefore, it is necessary to understand the failure mechanisms that occur in the material in order to ensure stability and durability. The effect of temperature and time of exposure on the impact and flexural mechanical responses of carbon/epoxy composites are studied in this work. For that purpose, ageing treatments at temperatures below and above the Tg have been considered and then, impact and flexural tests have been performed. It was observed that thermal ageing cause two different effects: at temperatures below the Tg, there is an increase of the maximum strength because of a post-curing effect; however, the mechanical properties decrease at higher temperatures of thermal ageing due to the thermo-oxidation of the epoxy resin and the loss of adhesion in the matrix/fibre interface.
Behnam Pourdeyhimi - One of the best experts on this subject based on the ideXlab platform.
-
characterisation and numerical modelling of complex deformation Behaviour in thermally bonded nonwovens
Computational Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Baris Sabuncuoglu, Vadim V. SilberschmidtAbstract:A complex time-dependent deformation and Damage Behaviour in polymer-based nonwovens are analysed under conditions of multi-stage uniaxial loading. Elastic–plastic and viscous properties of a polypropylene-based fabric are obtained by series of tensile, creep and relaxation tests performed on single fibres extracted from the studied fabric. These properties are implemented in a finite-element (FE) model of nonwoven with direct introduction of fibres according to their actual orientation distribution in order to simulate the rate-dependent deformation up to the onset of Damage in thermally bonded nonwovens. The predictions of FE simulations are compared with the experimental data of multi-stage deformation tensile tests and a good agreement is obtained including the mechanisms of deformation. Due to direct modelling of fibres based on their actual orientation distribution and implementation of viscous properties, the model could be extended to other types of polymer-based random fibrous networks.
-
Meso-scale deformation and Damage in thermally bonded nonwovens
Journal of Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Vadim V. SilberschmidtAbstract:Thermal bonding is the fastest and the cheapest technique for manufacturing nonwovens. Understanding mechanical Behaviour of these materials, especially related to Damage, can aid in design of products containing nonwoven parts. A finite element (FE) model incorporating mechanical properties related to Damage such as maximum stress and strain at failure of fabric’s fibres would be a powerful design and optimisation tool. In this study, polypropylene-based thermally bonded nonwovens manufactured at optimal processing conditions were used as a model system. A Damage Behaviour of the nonwoven fabric is governed by its single-fibre properties, which are obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that a single bond point was attached at both ends of each fibre. Additionally, similar tests were performed on unprocessed fibres, which form the nonwoven. Those experiments not only provided insight into Damage mechanisms of fibres in thermally bonded nonwovens but also demonstrated a significant drop in magnitudes of failure stress and respective strain in fibres due to the bonding process. A novel technique was introduced in this study to develop Damage criteria based on the deformation and fracture Behaviour of a single fibre in a thermally bonded nonwoven fabric. The Damage Behaviour of a fibrous network within the thermally bonded fabric was simulated with a FE model consisting of a number of fibres attached to two neighbouring bond points. Additionally, various arrangements of fibres’ orientation and material properties were implemented in the model to analyse the respective effects.
Memiş Acar - One of the best experts on this subject based on the ideXlab platform.
-
characterisation and numerical modelling of complex deformation Behaviour in thermally bonded nonwovens
Computational Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Baris Sabuncuoglu, Vadim V. SilberschmidtAbstract:A complex time-dependent deformation and Damage Behaviour in polymer-based nonwovens are analysed under conditions of multi-stage uniaxial loading. Elastic–plastic and viscous properties of a polypropylene-based fabric are obtained by series of tensile, creep and relaxation tests performed on single fibres extracted from the studied fabric. These properties are implemented in a finite-element (FE) model of nonwoven with direct introduction of fibres according to their actual orientation distribution in order to simulate the rate-dependent deformation up to the onset of Damage in thermally bonded nonwovens. The predictions of FE simulations are compared with the experimental data of multi-stage deformation tensile tests and a good agreement is obtained including the mechanisms of deformation. Due to direct modelling of fibres based on their actual orientation distribution and implementation of viscous properties, the model could be extended to other types of polymer-based random fibrous networks.
-
Meso-scale deformation and Damage in thermally bonded nonwovens
Journal of Materials Science, 2013Co-Authors: Farukh Farukh, Behnam Pourdeyhimi, Emrah Demirci, Memiş Acar, Vadim V. SilberschmidtAbstract:Thermal bonding is the fastest and the cheapest technique for manufacturing nonwovens. Understanding mechanical Behaviour of these materials, especially related to Damage, can aid in design of products containing nonwoven parts. A finite element (FE) model incorporating mechanical properties related to Damage such as maximum stress and strain at failure of fabric’s fibres would be a powerful design and optimisation tool. In this study, polypropylene-based thermally bonded nonwovens manufactured at optimal processing conditions were used as a model system. A Damage Behaviour of the nonwoven fabric is governed by its single-fibre properties, which are obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that a single bond point was attached at both ends of each fibre. Additionally, similar tests were performed on unprocessed fibres, which form the nonwoven. Those experiments not only provided insight into Damage mechanisms of fibres in thermally bonded nonwovens but also demonstrated a significant drop in magnitudes of failure stress and respective strain in fibres due to the bonding process. A novel technique was introduced in this study to develop Damage criteria based on the deformation and fracture Behaviour of a single fibre in a thermally bonded nonwoven fabric. The Damage Behaviour of a fibrous network within the thermally bonded fabric was simulated with a FE model consisting of a number of fibres attached to two neighbouring bond points. Additionally, various arrangements of fibres’ orientation and material properties were implemented in the model to analyse the respective effects.
