| 1. |
- Balieu, Romain, et al.
(författare)
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A new thermodynamical framework for finite strain multiplicative elastoplasticity coupled to anisotropic damage
- 2015
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Ingår i: International journal of plasticity. - : Elsevier BV. - 0749-6419 .- 1879-2154. ; 70, s. 126-150
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Tidskriftsartikel (refereegranskat)abstract
- The thermodynamical framework of an elastoplastic model coupled to anisotropic damage is presented in this paper. In the finite strain context, the proposed model is based on the multiplicative decomposition of the strain gradient into elastic and plastic parts. The anisotropic degradation is introduced by means of a second order tensor and another intermediate configuration is introduced by fictitiously removing this degradation from the plastic intermediate configuration. To enhance the physical meaning of the Mandel-like stress measure work conjugated to the inelastic flow stated in this fictitious configuration, i.e. the "effective stress", a new damage rate tensor is defined with its associated push-forward and pull-back operations. The emphasis in this paper is placed on the description of the interesting properties of the novel definitions of the push-forward and pull-back operations which are discussed through a thermodynamical framework. Furthermore, a specific constitutive model with the plastic and damage flow rules deduced from the restrictions imposed by the second law of thermodynamics is discussed with an application on an asphalt concrete material where the anisotropic evolution of the damage is highlighted.
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| 2. |
- Balieu, Romain, et al.
(författare)
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Damage at high strain rates in semi-crystalline polymers
- 2015
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 76, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A specific damage characterization method using Digital Image Correlation for semi-crystalline polymers is proposed for a wide range of strain rates. This damage measurement is an extension of the SEE method [16] which was developed to characterize the behaviour laws at constant strain rates of polymeric materials. This procedure is compared to the well-known damage characterization by loss of stiffness technique under quasi-static loading. In addition, an in-situ tensile test, carried out in a microtomograph, is used to observe the cavitation phenomenon in real time. The different ways used to evaluate the damage evolution are compared and the proposed technique is also suitable for measuring the ductile damage observed in semi-crystalline polymers under dynamic loading.
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| 3. |
- Balieu, Romain, et al.
(författare)
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Life Cycle Sustainability Assessment of Electrified Road Systems
- 2019
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Ingår i: ROAD MATERIALS AND PAVEMENT DESIGN. - Abingdon, UK : Taylor & Francis. - 1468-0629 .- 2164-7402. ; 20:sup1, s. S19-S33
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Tidskriftsartikel (refereegranskat)abstract
- The widespread use of Electric Vehicles (EVs) has been one of the main directionsfor pursuing a sustainable future of road transport in which, the deployment ofthe associated charging infrastructures, static or dynamic, has been included as oneof the main cornerstones for its success. Different electrified road (eRoad) systemswhich allow for dynamic charging of EVs by transferring electrical power from theroad to the vehicle in-motion, either in a conductive or contactless way, are underactive investigation. One of the important tasks in feasibility analysis of suchinfrastructure is to quantitatively assess its environmental performance and, thus,the consequential influences to the sustainability of road electrification as a whole.Having this concern in mind, in this study, a systematic LCA study is carried out in which the environmental impacts from the different life cycle stages have beencalculated and compared among several promising eRoad systems. In a next step,suitable strategies can be accordingly made to minimize these impacts in a most effectiveway; and more importantly, the LCA results of this study can serve as one ofthe important bases for conducting a more comprehensive and objective evaluationof the potential environmental benefits EVs could bring.
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| 4. |
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| 5. |
- Balieu, Romain, et al.
(författare)
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Multiplicative viscoelastic-viscoplastic damage-healing model for asphalt-concrete materials
- 2016
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Ingår i: RILEM Bookseries. - Dordrecht : Springer Netherlands. ; , s. 235-240
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Konferensbidrag (refereegranskat)abstract
- A viscoelastic-viscoplastic model based on a thermodynamic approach is developed under finite strain in this paper. By introducing a damage evolution, the proposed model is able to reproduce the behavior of Asphalt-Concrete materials until the complete fracture. Moreover, a recoverable part of the degradation is introduced to reproduce the self-healing observed under a sufficiently long rest period. The proposed model is implemented into a Finite Element code and good correlations between the numerical responses and the experiments have been observed.
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| 6. |
- Balieu, Romain, et al.
(författare)
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Non-associated viscoplasticity coupled with an integral-type nonlocal damage model for mineral filled semi-crystalline polymers
- 2014
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Ingår i: Computers & structures. - : Elsevier BV. - 0045-7949 .- 1879-2243. ; 134, s. 18-31
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Tidskriftsartikel (refereegranskat)abstract
- A non-associated viscoplastic model coupled with nonlocal damage under finite strain framework is developed to simulate the non-isochoric deformation and the damage process exhibiting strain-softening of a 20% mineral filled semi-crystalline polymer. The logarithmic spin tensor properties linking the Eulerian Hencky strain with the Cauchy stress is used thanks to hypoelasticity assuming the additive decomposition of the stretching into elastic and viscoplastic parts. The constitutive model with its nonlocal formulation is implemented in an efficient manner in a commercial implicit finite element code. The proposed model exhibits mesh-independent responses and is in agreement with strain evolution observed experimentally.
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| 7. |
- Bekele, Abiy, et al.
(författare)
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Micro-mechanical modelling of low temperature-induced micro-damage initiation in asphalt concrete based on cohesive zone model
- 2021
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618 .- 1879-0526. ; 286
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Tidskriftsartikel (refereegranskat)abstract
- Asphalt pavement is subjected to cyclic temperature variations during its service life owing to changes in daily and seasonal climatic conditions. These variations tend to accumulate thermally induced distress leading to initiation and evolution of micro-cracks. The effect of cyclic thermal variations as well as ther-mal incompatibility of mastic and aggregates is of major significance for understanding the behavior of thermally induced damage in pavements. Thermal stress is developed due to differential contraction of mastic relative to aggregates in asphalt concrete at low temperatures. In this paper, low temperature micro-damage initiation in asphalt concrete due to differential thermal contraction is modelled using 2D micro-mechanical volume element. Cohesive zone model (CZM) is adopted to simulate low temper-ature damage initiation at the mastic-aggregate interface (adhesive failure) within the mixtures. A cycle of cooling and heating is applied in the micro-mechanical model in order to capture the effect of thermal damage initiation on the overall stiffness modulus of the mixtures. The results from the model reveal a reduction in stiffness modulus (as compared to the values at similar temperatures within a cycle) after the temperature of-40 degrees C is reached within the applied cyclic cooling and heating. The effects of aggre-gate gradation and binder grade are also monitored by considering four cases of mixtures formed from a combination of two different gradations and two different mastics. Results of the micro-mechanical mod-elling are also compared with experimental observations of comparable mixture types.
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| 8. |
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| 9. |
- Belitz-Hellwich, Wiebke
(författare)
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An Ontology-Based Platform for Information Integration : Supporting Sustainable Smart Transportation Infrastructure
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transportation and transportation infrastructure are major contributors to global emissions. Even though most of these emissions can be attributed to fuel consumption of vehicles, some of it is due to pavement construction and maintenance. Improving the condition and extending the life span of transportation infrastructure is an integral part to helping reduce infrastructure related emissions. A better understanding of mutual effect of traffic and infrastructure condition is needed to reach this goal. In this thesis the aim is to synchronize logistics operations and pavement condition in a port environment. For this purpose, a logistics simulation model and a Finite Element (FE) model are connected through a system of ontologies, that facilitate information exchange between the models. The suggested approach consists of two connected ontologies (one for logistics operations and one for pavements), interfaces between the models and the ontologies, as well as an application that runs the exchange. Additionally, performance tests have been carried out to judge the impact of the integration on run time of the individual applications.
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| 10. |
- Chen, Feng, 1987-, et al.
(författare)
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A state-of-the-art review of intrinsic and enhanced electrical properties of asphalt materials: theories, analyses and applications
- 2020
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Ingår i: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197. ; 195, s. 109067-
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Tidskriftsartikel (refereegranskat)abstract
- In pavement engineering, a variety of promising application technologies are found relying on a thorough understanding of the intrinsic (mainly dielectric) electrical properties of asphalt binder and concrete materials. Meanwhile, the electrical properties of asphalt materials can be further enhanced by introducing conductive additives into and it has been brought to light that, the electrically conductive asphalt is becoming an emerging subject of interest that caters to the concept of a multifunctional pavement future. In context of these, this paper presents a holistic overview of the intrinsic and enhanced electrical properties of asphalt materials, including the theoretical analyses, as well as the corresponding applications in the practice. From such a state-of-the-art review, it is worth noting that: i) an improved understanding of asphalt material has been achieved by an in-depth examination of its electrical properties; ii) the increased significance of the research domain as a whole and, the key importance of multidisciplinary collaborations for future successes, have been indicated.
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