Oxide-Oxide Ceramic Matrix Composite simulation of continuum damage and fatigue failure response

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Project DescriptionThe programme will be ostensibly split into two parts:1. Investigate and downselect a method for non-linear analysis of ox/ox CMCsBuild on methods developed for SiC/SiC CMCs under CEMTEC and OMCs Focus on 2D bi-directional fabric reinforced composites, but with awareness that cross-ply ATL composites are in development. Fabric property distribution should be included; constitutive property inputs should be defined for testing, possibly as part of larger R-R programme.Investigate/adapt the Mori-Tanaka material homogenisation meso-scale model, for three phase system (fibre, matrix, porosity), to account for Ox/Ox CMC damage mechanics, such as handling micro and macro porosity (by element introduction to model macroporosity explicitly). Develop method for introduction of meso-scale input into macroscale engineering model for feature assessment via a sub-volume homogenisation approach. High fidelity macro-scale models are not expected to be needed.Explore UoB CZM formulations for application to ox/ox CMCs for static (monotonic) loading - through-thickness compression enhancement, non-local CZM, On-the-fly Insertion of Cohesive Segments,Explore CDM smeared crack models and 'directed' smeared crack models.2. Develop appropriate fatigue modelling approach based on ox/ox CMC characteristicsReview/appraise published fatigue modelling work by ONERA. Compare to smeared crack Continuum Damage Models including directed CDM and downselect.Compare, contrast and downselect from previous UoB approaches to fatigue modelling:o Explicit fatigue CZM, non-local fatigue CZM formulation, fatigue CZM with 4-IP elements, double envelope method, fully-reversed fatigue loading (often representative of real component aero surface loading), CZM for delamination growth, broad spectrum fatigue encompassing complex vibrational loadingThe fatigue approach should be built upon the framework developed in the first activityObjectivesTwo material revisions will be explored; CMCs will be manufactured from N610 1500 denier 8HS fabric or 4500 denier 5HS fabric, with an aluminosilicate matrix and similar constitutive volume fractions. Multiple materials sources may be possible if required.Year 1Downselection and development of most appropriate non-linear analysis method(s) for monotonic loadingYear 2Review CDM and CZM options for fatigue modelling, determine necessity for each, and develop downselected option(s)Year 3Bring together static and fatigue methods as workflow/tool to aid designer in structural integrity assessmentYear 4User manual, tool, GUI, thesis