Thursday, 10 December 10:00
The Maurice A. Biot Lecture Series -The speaker will be Prof. Jacques Huyghe, Bernal Institute.
The Maurice A. Biot Lecture was established at Columbia University in 2004 in remembrance of the late Professor Maurice Anthony Biot and his renowned achievements as an engineer, physicist, and applied mathematician. Biot was a professor of mechanics at Columbia University in the period 1937-1945.
The title of this webinar is: “Poromechanics in extremely large deformation: S welling and fracture”
Abstract: Unlike geomechanicists, biomedical engineers face porous media with very low stiffness, high osmolarity and extremely large deformations. Examples are superabsorbent hydrogels and living cells. Volume strains above 1000 % strain are commonplace in diapers, female pads and growth plates. The strong nonlinearities of large deformation formulations of poromechanics hamper the use of analytical solutions. Large deformation u-p formulations fail in this regime. This means that simulation tools of poromechanics are inapt to a great deal of biology, which typically unfolds in the intracellular space. Local mass balance violation is believed to be the culprit under extremely large deformations. In order to address this issue, we developed a mixed hybrid formulation of poromechanics of swelling gel based on a Raviart-Thomas finite element. This formulation strictly complies with local mass balance. Swelling computations are possible down to a shear modulus of 10 kPa. Surface instabilities easily develop as osmotic forces overtake the stabilizing effect of the elasticity. Fracture simulation using large deformation XFEM including flow within the crack, between the crack and the formation and within the crack, allows for initiation, coalescence and bifurcation of cracks. XFEM computations predict experimentally observed staccato propagation of cracks in hydrogels. Constitutive modelling of swelling require the concurrent use of elastic, mixing and ionic energies in Flory-Rehner swelling model. Interaction terms between elastic and ionic energies occur because the stiffness of gels directly depends on ionic concentrations. Future perspectives on constitutive modelling of swelling and fracturing gels are a natural continuation of Biot’s legacy.
Bio: Jacques Huyghe holds a Master degree in Civil Engineering from Ghent University, Belgium (1979) and a Ph.D. from Eindhoven University of Technology, The Netherlands. Jacques Huyghe has a unique signature in that he has been working at the interface between biomedical and petroleum engineering. He advertised repeatedly the close analogies between biological tissues and geomaterials and the urgent need to exploit these analogies in developing numerical models and industrial/clinical technologies. He authors more than 125 full-size SCI-publications, is the recipient of many awards among which a Royal Dutch Shell donation (1995-1998), a fellowship of the Royal Netherlands Academy of Arts and Sciences (1996-2001) and a swelling materials Interpore Award (2013). He has been cooperating with many industrial partners among which Philips Research, Shell Research and Procter and Gamble. His present interest is in mechanotransduction through voltage gated ion channels in intervertebral disc, swelling and fracture of superabsorbents and poromechanical modelling of coronary blood flow and microvascular flow of red blood cells.