Nikolas Zacharopoulos

University of the Aegean · Department of Product and Systems Design Engineering

This paper aims to provide new knowledge in the field of mycelium both in the context of DIY and Biofabrication. The approach of Biofabrication is closely tied with the transition towards sustainability and ways of designing that incorporate different values and aesthetics. At the same time, closing the material loops is a prerequisite of the circu...

One prominent strategy in achieving sustainability is upcycling, which is necessary for the transition of a post waste society. Craft has adopted the different ways of being in the world and can act as agent of change in the direction of sustainment. This study started with the aim to answer the question " Can I make something with this material, a...

We present a simulation procedure for fracture that self-consistently accounts for dislocation emission, dislocation migration and crack growth. We find that the dislocation microstructure in front of the crack tip is highly organized and shows a complex temporal-spatial evolution. The final dislocation microstructure and the number of emitted disl...

A Monte Carlo simulation procedure is applied to simulate non-uniform grain growth during directional annealing. The assumed temperature profile consists of a small, finite size hot zone which blends smoothly into cold zones ahead and behind the hot zone. The hot zone is assumed to move with a constant velocity. The influence of the ratio of hot zo...

The large length and time scales involved in polymer simulation render the atomistic representation of polymer systems a computationally expensive and unnecessarily detailed procedure. We present a novel coarse-graining method for the description of nonbonded interactions between moieties composing the monomeric units of polymers, phenyl rings in p...

We present results from discrete dislocation simulations showing the development of the plastic zone in front of a Mode III crack under constant load. We find that the equilibrated zone is circular, in agreement with continuum mechanics predictions of the elastic-perfectly plastic Mode III crack. The size of the equilibrated zone scales as the squa...

Molecular dynamics simulations are performed on generations 2 (G2) through 5 (G5) of poly(propylene imine) dendrimers at 400 K in order to investigate characteristics of molecular structure and morphology in the melt. As the generation increases, the dendrimers assume a more spherical shape, and the degree of dendron overlap increases, albeit at a...

Most derivations of grain growth relations require an assumption of constant grain boundary mobility; in fact, a number of these relations cannot be derived if boundary mobility varies in space or time. Computer simulations of grain growth in which boundary mobility varies in time and/or space have been performed. When mobility varies continuously...

We have developed a new, self-consistent simulation method for modeling crack growth with dislocation generation and motion in constant-loading-rate, Mode-III fracture. The dislocations emitted from the crack initially self-organize and propagate in very sharply defined lines. These lines undergo bifurcations, forming multiple new branches and shor...

A new, self-consistent, simulation method for modeling mode III crack growth and the evolution of the plastic zone is presented. The simulations are inherently two-dimensional since the dislocations are all of screw type and oriented parallel to the crack front. Under constant loading rate and unrestricted glide conditions, the dislocations emitted...

We present a simulation procedure for fracture that self-consistently accounts for dislocation emission, dislocation migration and crack growth. We find that the dislocation microstructure in front of the crack tip is highly organized and shows a complex temporal-spatial evolution. The final dislocation microstructure and the number of emitted disl...

The influence of cathodic hydrogen charging on some mechanical properties of copper was studied. Hydrogen charging was found to decrease both the ultimate tensile strength and the failure strain of copper. The surface layers of copper were hardened, but they recovered to their prior hardness with time passed after hydrogen charging.