3D cellular automata finite element (CAFE) modelling and experimental observation of damage in quasi-brittle nuclear materials: Indentation of a SiC-SiC fibre ceramic matrix composite

Authors: Luis Saucedo Mora (University of Oxford) , Mahmoud Mostafavi (University of Sheffield) , Danial Khoshkhou (University of Birmingham) , Christina Reinhard (Diamond Light Source) , Robert Atwood (Diamond Light Source) , Shuang Zhao (National University of Defence Technology, China) , Brian Connolly (University of Birmingham) , James Marrow (University of Oxford)
Co-authored by industrial partner: No

Type: Conference Paper
Conference: OECD Nuclear Energy Agency International Workshop on Structural Materials for Innovative Nuclear Systems 2013
Peer Reviewed: No

State: Published (Approved)
Published: October 2013
Diamond Proposal Number(s): 7730

Abstract: Cellular Automata integrated with Finite Elements (CAFE) have been used to develop a method to account for the effect of microstructure on quasi-brittle damage development. The microstructure is simulated explicitly by subdividing a finite element into smaller cells. A heterogeneous structure is created from key cells (seeds) using defined characteristics; the influence of the initial finite element mesh is effectively removed during the development of the microstructure. Graded microstructures, textures, particle anisotropy and multiple phases can be readily simulated, such as those in composites and porous materials. A mesh-free framework has been developed to compute the damage development through the microstructure, using cellular automata. With this method, we can study the development of discontinuous cracking and damage coalescence, and its sensitivity to microstructure. Experiments have been carried out to observe the three-dimensional development of damage, using high-resolution synchrotron X-ray computed tomography and digital volume correlation to observe Hertzian indentation of a SiC-SiC fibre composite, quantifying damage by measurement of the displacement fields within the material. The results demonstrate the applicability of the modelling strategy to damage development, and show how model input data may be obtained from small specimen tests, which could be performed at elevated temperatures with irradiated materials.

Journal Keywords: Computed Tomography; Hardness; Indentation; Digital Image Correlation

Subject Areas: Materials, Engineering

Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

Added On: 24/09/2013 10:17

Discipline Tags:

Materials Engineering & Processes Materials Science Engineering & Technology

Technical Tags:

Imaging Tomography