Fracture toughness and Impact Strength | Dental Materials

In this video Dr. Mujtaba Shaikh talks about the concept of Fracture Toughness and Impact Strength, related to Dental Materials.
The book followed for all the lectures of Dental Materials is, Applied Dental Materials Science by Mc Cabe.
Buy your textbook of Applied Dental Materials today, if you still haven't.
Here's the link:
amzn.to/4dg3OqL
We are currently on Chapter 2, which is the Properties Used to Characterize Dental Materials.
Quiz:
Q.1. How do we rule out external factors like air abrasion and friction during Charpy Impact Testing?
(a) By creating a notch in specimen
(b) Through a dummy run on the machine
(c) By subtracting estimated values after the test
Q.2. Out of the following, which type of material would have lesser values of fracture toughness?
(a) Ductile material
(b) Elastic material
(c) Malleable material
(d) Brittle material
Q.3. If a material falls on the floor from a noticeable height and fractures right away, it would have?
(a) greater impact strength
(b) lesser impact strength
(c) greater fracture toughness
(d) lesser fracture toughness
Q.4. Crack propagation may influence a material by:
(a) increasing fracture toughness
(b) decreasing fracture toughness
Q.5. If a test specimen fractures after intentionally introducing a v-shape dent or cracks, it is called a:
(a) Plastic material
(b) Elastic material
(c) Weak material
(d) Notch-sensitive material
Sources:
Charpy Impact tester video: • Charpy Impact Test
Charpy Impact tester image: www.totalmateria.com/page.asp...
Charpy Notch image: www.impact-solutions.co.uk/im...
Disclaimer:
Please note that the graphics, pictures and additional video contents used are not an intellectual property of The Dentalist and are only added for educational purposes, with no intention to violate copyrights.

[@fatimazaidi7298]

Sir just keep making videos.....you develope my interest in a subject like dental material and please complete this chap ASAP. Your hardwork is truly appreciated :)

[@TheDentalistt]

Thanks a lot! Definitely completing it asap and not stopping this time. Thanks for your comment, gives us great motivation ☺️

[@alexandraandronik7479]

please don`t stop making this videos!!!!!!!!!!

[@alizayfatimah6787]

Plz plz keep on making videos .
There is no other youtube channel which clears DM concepts like this ..

[@TheDentalistt]

Thanks will start again soon ☺️

[@sabramamji5890]

@@TheDentalistt Still waiting 🥺

[@sana_art_vlogs1996]

Q1-b, Q2- d, Q3-b, Q4-b, Q5-d

[@fatota3464]

Thank you so much

[@TheDentalistt]

You're welcome 😊

[@sairalakhani1659]

Sir do you teach from mccabe?

[@TheDentalistt]

Yes we are following Mc Cabe for all the lectures

[@fatimazaidi7298]

Sir, what is stress intensification factor and critical stress ???

[@TheDentalistt]

I would ask you to break this terminology, which would make it easier to understand, 'Stress' and 'Intensification'
Stress intensification factor of a material is a theoretical factor related to cracks/notches in a material, due to which stress is believed to be intensified in a material, causing an increase in the propagation of cracks, resulting in the material losing its dimension, or getting closer to its fracture point.
Stress intensification factor is formulated as Applied Stress X crack dimensions (length/width)
If a crack/notch size is 2 square meters and stress applied is 4 Pa.
Stress intensification factor would be 8
In situations where the crack size is larger, the stress intensification value would be greater, showing that the material has greater chances of bearing intensified stress, resulting in more crack propagation, and Ultimately losing its dimension.
In other words, If a material already has cracks or notches, a greater Stress intensification factor value would prove that it is easier for the cracks to propagate, that makes the material weaker and makes it easier for it to lose its shape, become dimensionally unstable or fracture.
Critical stress is the maximum stress applied after which the material tends to change its shape/dimensions
I hope it's clear. If you still have any confusions, please let me know. Thanks and all the best 👍

[@fatimazaidi7298]

@@TheDentalistt Got it....thanks a ton🙏🏼😊

[@humerafarooq6409]

Q1 b
Q2 d
Q3 b
Q4 b
Q5 d

[@jacinto1124]

😣 pr໐๓໐Ş๓