Solution to Exercise 5.2-2

Use the figures and draw in: 1. The force (direction and rough magnitude) acting on the dislocation with black and red for the two cases; 2. The position of the dislocation line after it has moved some distance.
Here is the completed picture. The last row shows some additional cases with reversed Burgers vector.
Of course, that the dislocations move "up" for the first two rows is an arbitrary choice as long as we don't define exactly how the sign of the Burges vector was obtained. Be that as it may, when we reverse the sign of the Burgers vector, forces and dislcotion movement also reverse signs.
Forces on dislocation

With frame With frame as PDF

go to Exercise 5.2-1 Displacement Field and Strain Tensor

go to Exercise 5.3-1 Dislocation Movement Around Obstacle

© H. Föll (Defects - Script)