Use this URL to cite or link to this record in EThOS:
Title: 3D CAFE modelling of transitional ductile fracture in steels
Author: Shterenlikht, Anton
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2004
Availability of Full Text:
Access from EThOS:
Access from Institution:
A coupled Cellular Automata - Finite Element (CAFE) three-dimensional multiscale model was applied in this work to the simulation of transitional ductile brittle fracture in steels. In this model material behaviour is separated from the representation of structural response and material data is stored in an appropriate number of cellular automata (CA). Two CA arrays, the "ductile" and the "brittle", are created, one is to represent material ductile properties, another is to account for the brittle fracture. The cell sizes in both arrays are independent of each ot her and of the finite element (FE) size. The latter is chosen only to represent accurately the macro strain gradients. The cell sizes in each CA array are linked to a microstructural feature relevant to each of the two fracture mechanisms. Such structure of the CAFE model results in a dramatic decrease of the !lumber of finite elements required to simulated the damage zone. Accordingly the running times are cut down significantly compared with the conventional FE modelling of fracture for similar representation of microstructure. The Rousselir continuing damage model was applied to each cell in the ductile CA array. The critical value of the maximum principal stress was used to assess the failure of each cell in the brittle CA array. The model was implemented through auser material subroutine for the Abaqus finite element code. Several examples of model performance are given. Among them are the results of the modelling of the Charpy test at transitional temperatures. For a laboratory rolled TMCR steel the model was able to predict the transitional curve in terms of the Charpy energy and the percentage of brittle phase, including realistic levels of scatter, and the appearance of the Charpy fracture surface. The ways in which material data can be fitted into the model are discussed and particular attention is drawn upon the significance of the fracture stress distribution.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available