Researchers at the Raman Research Institute (RRI), an autonomous institute of the Department of Science and Technology (DST), have been able to accurately predict the exact time of the emergence of the first crack in aged clay and blood — a finding that can aid in the diagnosis of conditions like anaemia.The study can also help in forensics and improving the quality of paints used for coatings.
Researchers studying material science at the RRI proposed a relation between the time of emergence of the first crack, fracture energy — which is the sum of the plastic dissipation and the stored surface energy — and the elasticity of the drying clay sample which can help predict the first crack.
They used the theory of linear poroelasticity, where they estimated the stress at the surface of the drying sample at the time of crack onset.
Linear poroelasticity is a theory for porous media flow that describes the diffusion of water (or any mobile species) in the pores of a saturated elastic gel.
The team equated the stress with Griffith’s criterion which states that a crack will grow when the energy released during propagation is equal to or greater than the energy required to create a new crack surface.
The research, published in the journal Physics of Fluids, detailed that the relation thus obtained was validated by performing a series of experiments. They further said that the same scaling relation worked for other colloidal materials such as silica gels.