ELFT HÍRADÓ

[Zsolt Kovács <kovacs.zsolt AT ttk.elte.hu>]

ELTE Fizikai Intézet, Anyagfizikai Tanszék TANSZÉKI SZEMINÁRIUM
*2022. november 15.*, kedd *8:30*-kor az ELTE Pázmány Péter sétány 1/A 
alatti épületében, a 4.52 (Sas Elemér) teremben, vagy online: Teams-en 
az Anyagfizikai Tanszék [TTK] csoportban *Kurunczi-Papp Dávid *(Tampere 
University)*Dislocation avalanches from strain-controlled loading: A 
discrete dislocation dynamics study *Minden érdeklődőt szívesen 
látunk,külsős vendégeink ezen a linken 
<https://teams.microsoft.com/l/meetup-join/19%3ad35c5af4a9344d05a080e330c26529df%40thread.tacv2/1668282865641?context=%7b%22Tid%22%3a%22b366dbcd-4fc3-4451-82d2-e239564302c3%22%2c%22Oid%22%3a%2287fe0ca6-4d26-4ef4-b521-fc5cc13203cb%22%7d> 
is tudnak csatlakozni az előadáshoz Kovács Zsolt ---------------------

Absztakt:

Plastic deformation of crystalline solids has been found to have a wildly 
fluctuating
and bursting character, directly observable as strain bursts with a broad 
size distribution
for micron-scale samples. I study strain-controlled plastic deformation of 
crystalline
solids via two- and three-dimensional discrete dislocation dynamics 
simulations.
To this end, I characterize the average stress-strain curves as well as the 
statistical
properties of strain bursts and the related stress drops as a function of the 
imposed
strain rate as well as the stiffness of the specimen-machine system in case 
of 2D simulations.
The sizes and durations of the dislocation avalanches are power law 
distributed up to a
cutoff scale, and exhibit temporally asymmetric average shapes. I discuss the 
dependence
of the results on the driving parameters and compare the results to those 
from previous
simulations where quasistatic stress-controlled loading was used. This 
characterization
of plastic deformation creates the exciting prospect of optimizing the 
mechanical properties
of materials by controlling the dislocation dynamics.