A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture
<p>The investigation of failure in brittle materials, subjected to dynamic transient loading conditions, represents one of the ongoing challenges in the mechanics community. Progresses on this front are required to support the design of engineering components which are employed in applicati...
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| Format: | Thesis |
| Language: | English |
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2017
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| _version_ | 1797093877055750144 |
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| author | Parrinello, A |
| author2 | Petrinic, N |
| author_facet | Petrinic, N Parrinello, A |
| author_sort | Parrinello, A |
| collection | OXFORD |
| description | <p>The investigation of failure in brittle materials, subjected to dynamic transient loading conditions, represents one of the ongoing challenges in the mechanics community. Progresses on this front are required to support the design of engineering components which are employed in applications involving extreme operational regimes. To this purpose, this thesis is devoted to the development of a framework which provides the capabilities to model how crack patterns form and evolve in brittle materials and how they affect the quantitative description of failure.</p> <p>The proposed model is developed within the context of diffusive interfaces which are at the basis of a new class of theories named <em>phase field models</em>. In this work, a set of additional features is proposed to expand their domain of applicability to the modelling of (i) rate and (ii) pressure dependent effects. The path towards the achievement of the first goal has been traced on the desire to account for micro-inertia effects associated with high rates of loading. Pressure dependency has been addressed by postulating a mode-of-failure transition law whose scaling depends upon the local material triaxiality. The governing equations have been derived within a thermodynamically-consistent framework supplemented by the employment of a micro-forces balance approach. The numerical implementation has been carried out within an updated lagrangian finite element scheme with explicit time integration. A series of benchmarks will be provided to appraise the model capabilities in predicting rate-pressure-dependent crack initiation and propagation. Results will be compared against experimental evidences which closely resemble the boundary value problems examined in this work. Concurrently, the design and optimization of a complimentary, improved, experimental characterization platform, based on the split Hopkinson pressure bar, will be presented as a mean for further validation and calibration.</p> |
| first_indexed | 2024-03-07T04:06:28Z |
| format | Thesis |
| id | oxford-uuid:c6590f4f-f4e2-40e3-ada1-49ba35c2a594 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:06:28Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | oxford-uuid:c6590f4f-f4e2-40e3-ada1-49ba35c2a5942022-03-27T06:37:23ZA rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fractureThesishttp://purl.org/coar/resource_type/c_db06uuid:c6590f4f-f4e2-40e3-ada1-49ba35c2a594Fracture mechanicsContinuum mechanicsImpact dynamicsContinuum damage mechanicsMaterialsMechanics--computational mechanicsEngineeringEnglishORA Deposit2017Parrinello, APetrinic, N<p>The investigation of failure in brittle materials, subjected to dynamic transient loading conditions, represents one of the ongoing challenges in the mechanics community. Progresses on this front are required to support the design of engineering components which are employed in applications involving extreme operational regimes. To this purpose, this thesis is devoted to the development of a framework which provides the capabilities to model how crack patterns form and evolve in brittle materials and how they affect the quantitative description of failure.</p> <p>The proposed model is developed within the context of diffusive interfaces which are at the basis of a new class of theories named <em>phase field models</em>. In this work, a set of additional features is proposed to expand their domain of applicability to the modelling of (i) rate and (ii) pressure dependent effects. The path towards the achievement of the first goal has been traced on the desire to account for micro-inertia effects associated with high rates of loading. Pressure dependency has been addressed by postulating a mode-of-failure transition law whose scaling depends upon the local material triaxiality. The governing equations have been derived within a thermodynamically-consistent framework supplemented by the employment of a micro-forces balance approach. The numerical implementation has been carried out within an updated lagrangian finite element scheme with explicit time integration. A series of benchmarks will be provided to appraise the model capabilities in predicting rate-pressure-dependent crack initiation and propagation. Results will be compared against experimental evidences which closely resemble the boundary value problems examined in this work. Concurrently, the design and optimization of a complimentary, improved, experimental characterization platform, based on the split Hopkinson pressure bar, will be presented as a mean for further validation and calibration.</p> |
| spellingShingle | Fracture mechanics Continuum mechanics Impact dynamics Continuum damage mechanics Materials Mechanics--computational mechanics Engineering Parrinello, A A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title | A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title_full | A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title_fullStr | A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title_full_unstemmed | A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title_short | A rate-pressure-dependent thermodynamically-consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| title_sort | rate pressure dependent thermodynamically consistent phase field model for the description of failure patterns in dynamic brittle fracture |
| topic | Fracture mechanics Continuum mechanics Impact dynamics Continuum damage mechanics Materials Mechanics--computational mechanics Engineering |
| work_keys_str_mv | AT parrinelloa aratepressuredependentthermodynamicallyconsistentphasefieldmodelforthedescriptionoffailurepatternsindynamicbrittlefracture AT parrinelloa ratepressuredependentthermodynamicallyconsistentphasefieldmodelforthedescriptionoffailurepatternsindynamicbrittlefracture |