research

The mechanical behavior of athermal random fiber networks embedding particulate inclusions is studied in this work. Composites in which the filler size is comparable with the mean segment length of the network are considered. Inclusions are randomly distributed in the network at various volume fractions, and cases in which fibers are rigidly bonded to fillers and in which no such bonding is imposed are studied separately. In the presence of inclusions, the small strain modulus increases, while the ability of the network to strain stiffen decreases relative to the unfilled network case.

Amit Acharya          Shankar Venkataramani

 (In Materials Theory)

Growth processes in many living organisms create thin, soft materials with an intrinsically hyperbolic
geometry. These objects support novel types of mesoscopic defects - discontinuity lines
for the second derivative and branch points - terminating defects for these line discontinuities.
These higher-order defects move "easily", and thus confer a great degree of
flexibility to thin hyperbolic elastic sheets. We develop a general, higher-order, continuum mechanical framework
from which we can derive the dynamics of higher order defects in a thermodynamically consistent
manner. We illustrate our framework by obtaining the explicit equations for the dynamics
of branch points in an elastic body.

https://www.researchgate.net/publication/333877242_Continuum_mechanics_of_moving_defects_in_growing_bodies

We've recently published our new study about Uncertainty Quantification in Molecular Dynamics (MD) Simulations. Due to the selection of functional forms of interatomic potentials or the numerical approximation, MD simulations may predict different material behavior from experiments or other high-fidelity results. In this study, we used Stochastic Reduced Order Modeling (SROM) to achieve

(1) mechanical behavior of graphene predicted by MD simulations in good agreement with the continuum model which has been calibrated by experiments;

I hope this work be of interest to some of you, in particular, those in the field of tribology, contact and damage mechanics. We examined the opposite contribution of interfacial adhesion into the process of surface material removal during adhesive wear. https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.3.063604

I hope some of you will find this work interesting. We present a new Weibull framework for cleavage fracture that incorporates strain gradient plasticity and can estimate the three parameters of Weibull-type models without any prior assumptions. A post-print is available at www.empaneda.com

Gradient-enhanced statistical analysis of cleavage fracture

Emilio Martínez-Pañeda, Sandra Fuentes-Alonso, CovadongaBetegón

European Journal of Mechanics - A/Solids 77, 103785 (2019)

The programmable shape transition of a two dimensional sheet to a three-dimensional (3D) structure in response to a variety of external stimuli has recently attracted increasing attention. Among the various shape changing materials, shape memory polymers (SMPs) can fix their temporary shape and/or their length and recover under proper thermal treatment.

Many living organisms undergo conspicuous or abrupt changes in body structure, which is often accompanied by a behavioral change. Inspired by the natural metamorphosis, robotic systems can be designed as reconfigurable to be multifunctional. Here, a tissue-engineered transformable robot is developed, which can be remotely controlled to assume different mechanical structures for switching locomotive function.

Title: Non-uniform curvature and anisotropic deformation control wrinkling patterns on tori