Publications de Paul Grandgeorge

The strength of surgical knots involves a critical interplay between friction and elastoplasticity

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Changyeob Baek

Knots are the weakest link in surgical sutures, serving as mechanical ligatures between filaments. Exceeding their safe operational limits can cause fatal complications. The empirical nature of present guidelines calls for a predictive understanding of the ...

AMER ASSOC ADVANCEMENT SCIENCE2023

Exploring the inner workings of the clove hitch knot

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We perform a combined experimental and computational investigation of the clove hitch knot. We develop a physical model for the clove hitch by tying an elastic rod onto a rigid cylinder. In the experiments, we characterize the mechanical performance, geome ...

ELSEVIER2022

An elastic rod in frictional contact with a rigid cylinder

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Tomohiko Sano

We investigate the load transmission along an elastic rod of finite cross-section in contact with a rigid cylinder, as system often referred to as the generalized capstan problem. In the presence of friction, the idealized classic capstan equation predicts ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Spontaneous formation of a self-healing carbon nanoskin at the liquid-liquid interface

Holger Frauenrath, Paul Grandgeorge, Enzo Jean Raymond Bomal, Nicolas Candau, Reuben Yeo Jueyuan, Pedro Miguel Nunes Pereira de Almeida Reis

Biological membranes exhibit the ability to self-repair and dynamically change their shape while remaining impermeable. Yet, these defining features are difficult to reconcile with mechanical robustness. Here, we report on the spontaneous formation of a ca ...

Nature Research2022

Mechanics of two filaments in tight orthogonal contact

John Maddocks, Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Harmeet Singh

Networks of flexible filaments often involve regions of tight contact. Predictively understanding the equilibrium configurations of these systems is challenging due to intricate couplings between topology, geometry, large nonlinear deformations, and fricti ...

National Academy of Sciences2021

The shapes of physical trefoil knots

John Maddocks, Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We perform a compare-and-contrast investigation between the equilibrium shapes of physical and ideal trefoil knots, both in closed and open configurations. Ideal knots are purely geometric abstractions for the tightest configuration tied in a perfectly fle ...

2021

Finite Element Modeling of Tight Elastic Knots

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We present a methodology to simulate the mechanics of knots in elastic rods using geometrically nonlinear, full three-dimensional (3D) finite element analysis. We focus on the mechanical behavior of knots in tight configurations, for which the full 3D defo ...

2020