School of Engineering

Event items

Simulation of multi-scale behaviour of plain and fibre reinforced cementitious composite materials

Speaker: Dr Iulia Mihai (Cardiff University)

Date/Time: Wednesday 23 Januiary 2019; 13:00-14:00

Venue: Cassie Building Room 2.32

The behaviour of cementitious composite materials is governed by complex cracking processes across multiple scales. Classic macroscopic constitutive models for these materials are largely based on empirical functions and they do not, in general, properly capture all of the physical mechanisms that control the complex behaviour. Moreover these models also require multiple parameters which can vary significantly when calibrating them using data from different experiments, yet have a strong influence on the predicted behaviour. Techniques in which the micro and meso-structure of the composite is represented discretely have been developed and these can capture well the cracking processes as well as the characteristic behaviour. However, their very large computational cost make them inefficient or even unsuitable for large scale simulations. Ideally, efficient non-linear finite element simulations would make use of continuum based constitutive models that are able to capture the underlying physical mechanisms.

The talk will focus on an alternative, mechanics-based approach, the aim of which is to capture characteristic mechanical behaviour by simulating simple physical mechanisms at the micro or meso-scale. The constitutive models presented employ a range of Eshelby type continuum micromechanics solutions to represent material phases and micro-cracking processes as well as a rough crack contact component. Furthermore, for fibre reinforced cementitious materials the bridging action of randomly distributed short fibres will be addressed by employing a local constitutive relation that accounts for the debonding and pull-out of fibre groups with different orientations. The performance of the models will be demonstrated with a series of examples.

Dr Iulia Mihai