# Finite Element modeling

The winner of the 2019 Robert J. Melosh Medal is Dewen Yushu (University of Notre Dame), who presented the paper "The data-driven multiscale multigrid solver, preconditioner and reduced-order model."

Congratulations also to the other finalists! They are listed below, with their respective papers:

Siddhant Kumar, California Institute of Technology and ETH Zurich "Enhanced local maximum-entropy approximation for stable meshfree simulations;"

Check out our latest publication on porcine liver biomechanics under high strain rate conditions -

"Mechanical Response of Porcine Liver Tissue under High Strain Rate Compression", Bioengineering, 2019, 6(2), 49; https://doi.org/10.3390/bioengineering6020049

https://www.mdpi.com/2306-5354/6/2/49

Dear imechanicians

I hope that this paper is of interest to you. The phase field fracture code developed in FEniCS is available at www.empaneda.com/codes

Phase field modelling of crack propagation in functionally graded materials

Hirshikesh, S. Natarajana, R.K. Annabattula, E. Martínez-Pañeda

Composites Part B: Engineering 169, pp 239-248 (2019)

A PhD position is available at LaSie (La Rochelle University, France), until oct. 2019.

The work will be dedicated to the caracterisation (numercial and experimental) of the effect of grains boundary on the Hydrogen diffusion in Nickel polycrystals.

Please send your resume and application letter to:

J. Bouhattate (Jamaa.bouhattate [at] univ-lr.fr)

The Postdoctoral Scholar is responsible for independent and collaborative development, implementation, and analysis of scientific research in the discipline of computational and experimental biomechanics. Responsibilities include management of all aspects of research related to biomechanical characterization and computer modeling of biological tissue and implants in Vahdati Lab. The research projects include investigation of mechanopathologies of soft and calcified tissue and design of personalized medical devices.

We are looking for a talented, self-motivated, and enthusiastic student with a BSc or MSc degree in mechanical or materials engineering. Students with strong background in crystal plasticity and computational mechanics are recommended to apply.

Prospective candidates will be assessed based on how well they meet the following criteria:

§  Excellent degree in their relevant discipline;

§  Excellent written and spoken communication skills (iBT TOFEL score must be higher than 86, with no individual score below 20)

Solving incompressible elasticity has been quite challenging numerically. The conventional approach for handling incompressibility is the so-called penalty method. A volumetric energy term enters into the strain energy and penalizes the volumetric deformation. One straightforward issue is that the penalty parameter goes directly into the tangent matrix. The bigger the penalty parameter, the worse the condition number of the matrix. This is really a manifestation of the ill-posedness of theories based on the Helmholtz free energy, in my opinion [3].

I hope some of you may find this work interesting. We show that kinematic hardening effects play a significant role in monotonic/static fracture.

Steady-state fracture toughness of elastic-plastic solids: Isotropic versus kinematic hardening

K.J.Juul, E.Martínez-Pañeda, K.L.Nielsen, C.F.Niordson

Engineering Fracture Mechanics, 207, pp. 254-268 (2019)

Volume 207, 15 February 2019, Pages 254-268