Material and structural behavior are simulated
by means of a multiscale approach involving both microscopic and macroscopic
scales. The goal is to integrate testing and simulations to develop
computational models with predictive capabilities.
Bending, tensile and fractural tests are
conducted to study the mechanical behavior of FGMs. The measured parameters
are used as input for special constitutive models of our finite element
Rheological properties of the fresh
cement-based composites are crucial to the successful extrusion processing.
Extrusion of functionally graded fresh cement-based composites is far more
difficult than extrusion of monolithic material. The relative rheological
properties of different layers of paste need to be adjusted distinctively.
Extrusion processing produces microstructural
features with special characteristics, which in turn influence the material
properties. In this study, a micro-CT is
used to investigate the actual 3-D microstructure of novel fiber-reinforced
cement-based FGMs. Thus real 3-D microstructural measurements (e.g. fiber
distribution & orientation, porosity) are obtained from the image analysis.
A lab-scale ram extruder was made to manufacture
the functionally graded material. Connected to an Instron machine, the
pressure and the extrusion speed can be well controlled giving more
flexibility than a standard commercial extruder.
Other than single-run extrusion, re-extrusion
and co-extrusion method will be used to exploit the full benefit of
extrusion technique. It is expected that the FGM will be much denser in
matrix and much stronger in interface between different layers.