Speaker
Description
The reinforcement of alumina-based ceramic matrix composites (CMCs) with low dimensional phases such as carbon nanotubes (CNTs) is still an open research topic because of their potentiality as reinforcement phases for tougher materials. Despite decades of research, some experimental issues such as the dispersion of the CNTs, their intra/intergranular location, or the bonding between CNTs and the matrix, are still hindering the achievement of unquestionable reinforcements [1,2]. Moreover, there is still a lack of conclusive results which show the actual relevance of the mentioned experimental problems or the limit theoretical reinforcement that can be expected.
This work is concerned with the development and exploitation of a simulation tool that explores the structural performance of the CMCs. To do so, a Finite-Element-Method based procedure already employed to simulate fracture experiments by tensile tests of polycrystalline silicon is being adapted [3]. Firstly, 2D Voronoi tessellations with different average grain size are built via the software Neper [4], with the aim of emulating the log-normal grain size distributions of polycrystalline alumina matrix. The fracture of the grain bulk and its boundaries will be characterized with an anisotropic phase-field framework coupled with traction-separation laws. Physical consistency is checked by reproducing some grain-size dependences of the alumina such as Hall-Petch effect, or by comparison with own and reported results of the transgranular/intergranular fracture type ratio. Finally, the simulation research is focused on the influence of the different characteristics such as the amount of CNTs, their location, or type of bond between CNT and the matrix, on the composite toughness.
[1] Ceram Int 2016;42:2054–62
[2] Ceram Int 2020;46:19723–19730
[3] Comput Methods App Mech Engrg 2018;330:123‒148
[4] Comput Methods Appl Mech Engrg 2011;200:1729‒1745
| Speaker Country | España |
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