User login


You are here

Kamyar M Davoudi's blog

Kamyar M Davoudi's picture

Lecture 8: Dislocation Motion

These slides are used in a course on Plastic Deformation in Crystalline Solids.

Kamyar M Davoudi's picture

Lecture 7: Energy of Dislocations

These slides are used in a course on Plastic Deformation in Crystalline Solids.

Kamyar M Davoudi's picture

(Course) Plastic Deformation in Crystalline Solids

Instructor: Kamyar Davoudi

Lectures: Saturdays and Mondays, 10:30 am-12:00 pm

Institute: Sharif University


Kamyar M Davoudi's picture

Eighty Years of Dislocation Theory and Work Hardening

On February 7, 1934, two consecutive papers by Sir Geoffrey Ingram Taylor were received and so the dislocation theory was born and the first attempt at describing work hardening was made. Before that date, it was known that there was a big gap between the ideal and the experimentally observed shear strength. While according to the calculations, the shear strength had to be of the order of one tenth (or with finer models one thirtieth) of the shear modulus, the measured shear strength was several orders of magnitude smaller. This large discrepancy brought about Geoffrey I.Taylor, Egon Orowan and Michael Polyani to independently postulate the existence of dislocations. Papers by Orowan and Polyani were published consecutively in one volume of Zeitschrift für Physik.

Kamyar M Davoudi's picture

Dislocation Climb in Two-Dimensional Discrete Dislocation Dynamics

In this paper, dislocation climb is incorporated in a two-dimensional discrete dislocation dynamics model. Calculations are carried out for polycrystalline thin films, passivated on one or both surfaces. Climb allows dislocations to escape from dislocation pile-ups and reduces the strain-hardening rate, especially for fully passivated films. Within the framework of this model, climb modifies the dislocation structures that develop during plastic deformation and results in the formation of pile-ups on slip planes that do not contain any dislocation sources.

Kamyar M Davoudi's picture

Some books on Fracture Mechanics

Fracture Mechanics, Fundamentals and Applications, T.L. Anderson, CRC Press, 3rd Ed., 2004.

This book is in line with what Zhigang is teaching in class. Because Kejie and Widusha have already recommended this book, I would like to introduce you some other books as well as a different approach to cracks and Fracture Mechanics.

Kamyar M Davoudi's picture

Decomposition of the displacement gradient into elastic and plastic parts

We know that total strain is the symmetric part of the displacement gradient. Total strain can be represented by the sum of the elastic and plastic (eigen) strains. Let consider a dislocation in an arbitrary solid. Suppose we computed the displacement filed, therefore the total strain can be obtained immediately. What are the criteria for the decomposition of the total strain into elastic and plastic parts?


Subscribe to RSS - Kamyar M Davoudi's blog

Recent comments

More comments


Subscribe to Syndicate