The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Nigel Scott - One of the best experts on this subject based on the ideXlab platform.
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Orthotropic Cyclic Stress-softening model for pure shear during repeated loading and unloading
IMA Journal of Applied Mathematics, 2014Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:We derive an orthotropic model to describe the Cyclic Stress softening of a carbon-filled rubber vulcanizate through multiple Stress-strain cycles with increasing values of the maximum strain. We specialize the deformation to pure shear loading. As a result of strain-induced anisotropy following on from initial primary loading, the material may subsequently be described as orthotropic because in pure shear there are three different principal stretches so that the strain-induced anisotropy of the Stress response is different in each of these three directions. We derive non-linear orthotropic models for the elastic response, Stress relaxation and residual strain to model accurately the inelastic features associated with Cyclic Stress softening. We then develop an orthotropic version of the Arruda-Boyce eight-chain model of elasticity and then combine it with the ideas previously developed in this paper to produce an orthotropic constitutive relation for the Cyclic Stress softening of a carbon-filled rubber vulcanizate. The model developed here includes the widely occurring effects of hysteresis, Stress-relaxation and residual strain. The model is found to compare well with experimental data.
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A Cyclic Stress softening model for the Mullins effect
International Journal of Solids and Structures, 2013Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:Abstract In this paper the inelastic features of Stress relaxation, hysteresis and residual strain are combined with the Arruda–Boyce eight-chain model of elasticity, in order to develop a model that is capable of describing the Mullins effect for Cyclic Stress-softening of an incompressible hyperelastic material, in particular a carbon-filled rubber vulcanizate. We have been unable to identify in the literature any other model that takes into consideration all the above inelastic features of the Cyclic Stress-softening of carbon-filled rubber. Our model compares favourably with experimental data and gives a good description of Stress-softening, hysteresis, Stress relaxation, residual strain and creep of residual strain.
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Cyclic Stress-softening model for the Mullins effect in compression
International Journal of Non-Linear Mechanics, 2013Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:Abstract This paper models the Cyclic Stress softening of an elastomer in compression. After the initial compression the material is described as being transversely isotropic. We derive non-linear transversely isotropic constitutive equations for the elastic response, Stress relaxation, residual strain, and creep of residual strain in order to model accurately the inelastic features associated with Cyclic Stress softening. These equations are combined with a transversely isotropic version of the Arruda–Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during Cyclic Stress softening for a transversely isotropic, hyperelastic material, in particular a carbon-filled rubber vulcanizate. To establish the validity of the model we compare it with two test samples, one for filled vulcanized styrene–butadiene rubber and the other for filled vulcanized natural rubber. The model is found to fit this experimental data extremely well.
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Transversely isotropic Cyclic Stress-softening model for the Mullins effect
Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 2012Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:This paper models Stress softening during Cyclic loading and unloading of an elastomer. The paper begins by remodelling the primary loading curve to include a softening function and goes on to derive nonlinear transversely isotropic constitutive equations for the elastic response, Stress relaxation, residual strain and creep of residual strain. These ideas are combined with a transversely isotropic version of the Arruda–Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during Cyclic Stress softening for a transversely isotropic, hyperelastic material, in particular, a carbon-filled rubber vulcanizate.
Stephen R. Rickaby - One of the best experts on this subject based on the ideXlab platform.
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transversely isotropic Cyclic Stress softening model for the mullins effect
arXiv: Soft Condensed Matter, 2020Co-Authors: Stephen R. Rickaby, N H ScottAbstract:This paper models Stress softening during Cyclic loading and unloading of an elastomer. The paper begins by remodelling the primary loading curve to include a softening function and goes on to derive non-linear transversely isotropic constitutive equations for the elastic response, Stress relaxation, residual strain and creep of residual strain. These ideas are combined with a transversely isotropic version of the Arruda-Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during Cyclic Stress-softening for a transversely isotropic, hyperelastic material, in particular a carbon-filled rubber vulcanizate. Keywords: Mullins effect, Stress-softening, hysteresis, Stress relaxation, residual strain, creep of residual strain, transverse isotropy. MSC codes: 74B20, 74D10, 74L15
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Orthotropic Cyclic Stress-softening model for pure shear during repeated loading and unloading
IMA Journal of Applied Mathematics, 2014Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:We derive an orthotropic model to describe the Cyclic Stress softening of a carbon-filled rubber vulcanizate through multiple Stress-strain cycles with increasing values of the maximum strain. We specialize the deformation to pure shear loading. As a result of strain-induced anisotropy following on from initial primary loading, the material may subsequently be described as orthotropic because in pure shear there are three different principal stretches so that the strain-induced anisotropy of the Stress response is different in each of these three directions. We derive non-linear orthotropic models for the elastic response, Stress relaxation and residual strain to model accurately the inelastic features associated with Cyclic Stress softening. We then develop an orthotropic version of the Arruda-Boyce eight-chain model of elasticity and then combine it with the ideas previously developed in this paper to produce an orthotropic constitutive relation for the Cyclic Stress softening of a carbon-filled rubber vulcanizate. The model developed here includes the widely occurring effects of hysteresis, Stress-relaxation and residual strain. The model is found to compare well with experimental data.
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A Cyclic Stress softening model for the Mullins effect
International Journal of Solids and Structures, 2013Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:Abstract In this paper the inelastic features of Stress relaxation, hysteresis and residual strain are combined with the Arruda–Boyce eight-chain model of elasticity, in order to develop a model that is capable of describing the Mullins effect for Cyclic Stress-softening of an incompressible hyperelastic material, in particular a carbon-filled rubber vulcanizate. We have been unable to identify in the literature any other model that takes into consideration all the above inelastic features of the Cyclic Stress-softening of carbon-filled rubber. Our model compares favourably with experimental data and gives a good description of Stress-softening, hysteresis, Stress relaxation, residual strain and creep of residual strain.
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Cyclic Stress-softening model for the Mullins effect in compression
International Journal of Non-Linear Mechanics, 2013Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:Abstract This paper models the Cyclic Stress softening of an elastomer in compression. After the initial compression the material is described as being transversely isotropic. We derive non-linear transversely isotropic constitutive equations for the elastic response, Stress relaxation, residual strain, and creep of residual strain in order to model accurately the inelastic features associated with Cyclic Stress softening. These equations are combined with a transversely isotropic version of the Arruda–Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during Cyclic Stress softening for a transversely isotropic, hyperelastic material, in particular a carbon-filled rubber vulcanizate. To establish the validity of the model we compare it with two test samples, one for filled vulcanized styrene–butadiene rubber and the other for filled vulcanized natural rubber. The model is found to fit this experimental data extremely well.
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Transversely isotropic Cyclic Stress-softening model for the Mullins effect
Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 2012Co-Authors: Stephen R. Rickaby, Nigel ScottAbstract:This paper models Stress softening during Cyclic loading and unloading of an elastomer. The paper begins by remodelling the primary loading curve to include a softening function and goes on to derive nonlinear transversely isotropic constitutive equations for the elastic response, Stress relaxation, residual strain and creep of residual strain. These ideas are combined with a transversely isotropic version of the Arruda–Boyce eight-chain model to develop a constitutive relation that is capable of accurately representing the Mullins effect during Cyclic Stress softening for a transversely isotropic, hyperelastic material, in particular, a carbon-filled rubber vulcanizate.
Hans Jürgen Maier - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Stress–strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
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Cyclic Stress strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
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Cyclic Stress–strain response and low-cycle fatigue damage in ultrafine grained copper
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Hans Jürgen Maier, P. Gabor, Ibrahim KaramanAbstract:Abstract We report on the fatigue behavior of ultrafine grained (UFG) copper obtained by equal channel angular extrusion (ECAE). Cyclic Stress–strain response and fatigue life data were determined in fatigue tests conducted in the low-cycle fatigue (LCF) regime. The early stages of the fatigue process were examined in a scanning electron microscope equipped with a small-scale load frame that allowed for in situ fatigue observations. The ECAE route 16E gives superior fatigue performances as it provides for stable Cyclic Stress–strain response and more homogeneous plastic deformation than routes that are composed of lower number of ECAE passes. Still, the in situ fatigue tests indicated that fatigue damage occurs on a very localized scale, and thus, additional strengthening mechanisms need to be exploited to obtain UFG materials that display enhanced microstructural stability.
M. Haouaoui - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Stress–strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
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Cyclic Stress strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
Ibrahim Karaman - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Stress–strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
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Cyclic Stress strain response of ultrafine grained copper
International Journal of Fatigue, 2006Co-Authors: Hans Jürgen Maier, P. Gabor, Nitesh Gupta, Ibrahim Karaman, M. HaouaouiAbstract:Abstract The present study reports on the Cyclic Stress–strain response of ultrafine grained copper obtained by equal channel angular extrusion (ECAE). Fatigue behavior of material subjected to between 8 and 16 ECAE passes was studied both in constant amplitude and incremental step tests. Transmission electron microscopy was employed to shed light on the microstructural evolution. Samples that had been extruded by an optimized ECAE route (16E) displayed stable Cyclic Stress–strain response. Independent of the actual Cyclic loading condition, all the ECAE processed material demonstrated near perfect Masing behavior indicating that the ECAE routes selected resulted in microstructures stable against fatigue-induced changes. This is in contrast to copper with conventional grain sizes. An additional heat treatment that resulted in a bimodal microstructure eliminated the differences in Cyclic response that had resulted from the various ECAE routes applied. Still, the bimodal structure proved to be Cyclically stable in strain-controlled tests conducted at room temperature. Preliminary studies from an in-situ tests conducted in a scanning electron microscope demonstrated that non-optimized ECAE routes will lead to rapid Cyclic instability, severe damage localization and premature fatigue failure.
-
Cyclic Stress–strain response and low-cycle fatigue damage in ultrafine grained copper
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Hans Jürgen Maier, P. Gabor, Ibrahim KaramanAbstract:Abstract We report on the fatigue behavior of ultrafine grained (UFG) copper obtained by equal channel angular extrusion (ECAE). Cyclic Stress–strain response and fatigue life data were determined in fatigue tests conducted in the low-cycle fatigue (LCF) regime. The early stages of the fatigue process were examined in a scanning electron microscope equipped with a small-scale load frame that allowed for in situ fatigue observations. The ECAE route 16E gives superior fatigue performances as it provides for stable Cyclic Stress–strain response and more homogeneous plastic deformation than routes that are composed of lower number of ECAE passes. Still, the in situ fatigue tests indicated that fatigue damage occurs on a very localized scale, and thus, additional strengthening mechanisms need to be exploited to obtain UFG materials that display enhanced microstructural stability.
