In the case of an edge dislocation, you can visualize a dislocation line using an extra half-plane of atoms. Screw dislocation line is harder to imagine. I recommend looking at more pictures, videos, and simulations to better understand the displacements they (both dislocations) cause in the lattice. A straightforward way to think of a dislocation line is as the boundary between the slipped and unslipped regions. This will help to understand the nature of burgers vector and dislocation line vector.

Himanshu, These points are useful when considering plasticity under various conditions. Points A and B are particularly valuable for theoretical work on the onset of plasticity. In contrast, points Y and P are mainly relevant for practical applications. To fully understand the definition of yield and the utility of Point P, I recommend reading textbooks by R. M. Christensen.

@@nirajchawake thankyou very much sir😊

I used various books on mechanical behaviour of Materials by Dieter, Meyers and Chawla, Hosford, Courtney.

Please check this video kzbin.info/www/bejne/paKmnaFmZcaXsK8si=xaJ6GrRsqFyloRT_

Our objective is to establish a connection between stress and strain behavior and the motion of dislocations. In this context, we understand that dislocations glide or slip along specific planes, resulting in shear strain. These movements are governed by the shear stress acting on these glide planes. Therefore, for simplicity, we concentrate on investigating shear stress and shear strain in this scenario.

😂😊

@@euniceikwanga 🦺😊

Let's consider a steel cylinder with dimensions: length 100 mm and radius 10 mm, under a tensile load of 1 N, with an elastic modulus of 200 GPa. To determine the stress and strain, we apply basic definitions: Stress = Force/Area = 1 N / (π × 10^2) mm^2 = 0.0032 MPa Strain = Stress / Elastic modulus = 0.0032 MPa / 200 GPa = 1.6E−8 This yields a strain of 1.6E−8, which can also be expressed as the change in length/original length: Change in length = 1.6E−8 × 100 mm = 1.6E−9 m = 1.6 nm Despite being a minute value, it demonstrates that even small forces induce an elastic response in terms of stress and strain. Thus, the statement, "forces acting on a body causing stresses in it but won't cause strains," is inaccurate. As materials inevitably respond to stress with associated strains.

@@nirajchawake Thankyou so much sir for responding..... One more thing is here ,you used the word "Inaccurate" . Were you wanted to use insignificant??? Because here how inaccurate will make sense?? We are getting accurate value,by putting all the data you mentioned in reply.

its a typo

Glad that it is useful to you

please email me at nchawake[at]iitk[dot]ac[dot]in

We don't have studies related to this. Please feel free to use photos by giving proper credits. Also, if you use photos/images from the video which I have taken from other sources, please see the references mentioned at the bottom of slides for them.

May be a mistake there. Dislocation always moves perpendicular to the dislocation line (or its tangent vector).

Thank you for the clarification. Great educational videos, especially the visualisations.

Thanks a lot for your comment. My best wishes and happy learning :)