The fracture of concrete and other semi-brittle materials offers some simplifications that simplify the analytical analysis. The simple check that reveals if something broken requires an elastic or an elastic-plastic fracture mechanical analysis by just trying to fit the pieces together sometimes fails. The suggestion is that if they do not fit together, we have an elastic-plastic fracture and if they do we have an elastic fracture. We may jump to the false conclusion that linear elastic fracture mechanics can be applied.

The Gu Research Group at UC Berkeley has postdoc positions available in the areas of computational fluid dynamics, aerodynamics, and aeroelasticity. Interested candidates should contact Prof. Grace Gu at ggu [at] berkeley.edu and attach your CV. 

Postdoc positions are available in Dr Min Luo’s group (https://person.zju.edu.cn/en/minluo) at the Ocean College of Zhejiang University, China (ranked #45 in QS Global World Rankings 2022). Those holding a PhD degree in the areas of Computational Fluid Mechanics and Civil/Hydraulic/Ocean Engineering are welcome to apply.

1.    Project description

The transition between necking-mediated tensile failure of glasses, at elevated temperatures

and/or low strain-rates, and shear-banding-mediated tensile failure, at low temperatures and/or

high strain-rates, is investigated using tensile experiments on metallic glasses and atomistic simula-

tions. We experimentally and simulationally show that this transition occurs through a sequence of

macroscopic failure patterns, parametrized by the ultimate tensile strength. Quantitatively analyz-

Understanding the fracture toughness of glasses is of prime importance for

science and technology. We study it here using extensive atomistic simulations in

which the interaction potential, glass transition cooling rate, and loading geometry

are systematically varied, mimicking a broad range of experimentally accessible

properties. Glasses’ non-equilibrium mechanical disorder is quantified through

A_g, the dimensionless prefactor of the universal spectrum of non-phononic

In this project, the research fellow is expected to work on the K&C concrete model in LS-DYNA. Focusing on normal strength concretes of ~45 to 60 MPa compressive strengths, the research fellow has to calibrate the material parameters against experimental data, and to establish all modelling inputs for simulating the response of concrete structures against very high impact loading conditions. The numerical predictions will be benchmarked against experimental data.

The Laboratory for Fluid-Structure Interaction (LIFE) (http://labfsi.com/) of the Department of Mechanical Engineering at the Universitat Rovira i Virgili (URV) (www.urv.cat) in Tarragona (Spain), is looking for an enthusiastic research student with a strong interest in fluid dynamics and fluid-structure interactions. Successful candidates will join a small but very active multidisciplinary team, working in several fluid-structure interaction (FSI) problems.

We developed an inverse design method for constructing 3D reconfigurable architected structures — we synthesized modular origami structures whose unit cells can be volumetrically mapped into a prescribed 3D curvilinear shape followed by volumetric shrinkage for constructing modules. After modification of tubular geometry, we searched modular origamis’ geometry and topology for target mobility using a topological reconstruction of modules.

Traditionally dynamic analysis is done using Newton’s universal laws of the equation of motion. According to the laws of Newtonian mechanics, the x, y, z, space-time coordinate system does not include a term for energy loss, an empirical damping term “C” is used in the dynamic equilibrium equation. Energy loss in any system is governed by the laws of thermodynamics. Unified Mechanics Theory (UMT) unifies the universal laws of motion of Newton and the laws of thermodynamics at ab-initio level.

Dear Colleagues,