Shadowing Practice: Material Properties 101 - Learn English Speaking with Video
Creando lección...
1
This video is going to be a bit different to my usual videos, but I want to talk about material properties and the words we use to describe them.
2
This is information you are going to need to fully understand future videos.
3
By the end of this video, I want you to understand 6 keywords that we use to describe materials.
4
These are stiff, strong, ductile, brittle, tough and hard.
5
With these words, you will be able to describe pretty much any material
6
and better understand why certain materials are used in different applications.
7
More technical videos like this will be uploaded to my second channel from now on, which you can subscribe to by following this link.
8
I'll try and back up the technical stuff with interesting real-world examples.
9
First we are going to learn what a tensile test is.
10
A tensile test is a fundamental test in material mechanics.
11
It's performed by pulling a sample of material apart until failure, while measuring the force and displacement.
12
It provides us with something called a stress strain curve, which tells us a lot about the material's reactions to forces.
13
In this scenario, the stress is defined by the force applied to the test sample, divided by the cross-sectional area.
14
This gives us units of newtons per meter squared, which you may recognize as the metric unit for pressure, Pascals.
15
Stress goes on the y-axis.
16
Strain describes how much deformation has occurred with that applied force, and it is found by dividing the change in length by the original length.
17
This is placed on the x-axis.
18
Let's watch this test again and see what information we can get from the stress strain graph.
19
As the stress rises, the material begins to deform.
20
This initial linear region is elastic deformation, That means if we remove the force, the material will regain its original shape.
21
Think of how a rubber band can deform hugely and still come back to its original shape.
22
The end of this linear elastic deformation is marked by the yield point.
23
From here out, any additional stress will cause permanent deformation.
24
This is called plastic deformation.
25
The stress continues to rise until it hits the ultimate tensile strength point.
26
This is the ultimate strength of the material, the most stress it can handle.
27
From here, less stress is needed as the material begins to decrease in cross section, which you can see happening here.
28
This is called necking.
29
This continues until the material fractures.
30
We can get a lot of really useful information from this graph.
31
The first is Young's modulus, otherwise known as the elastic modulus.
32
This describes how stiff the material is, and it is obtained by finding the slope of this linear region.
33
A steeper slope means a stiffer material.
34
For example, a high carbon steel may look like this, whereas a flexible material with the low Young's modulus, like rubber, would look like this.
35
This graph is not to scale, but it should give you an idea of how this information is represented.
36
Young's modulus is one of the most used properties in engineering, as we can use it to predict deflection in a huge range of scenarios.
37
Yield strength and ultimate tensile strength are two other important properties.
38
An engineer will divide the yield or ultimate strength by the safety factor to achieve the max allowable stress, which is used to influence the design of the product.
39
Usually engineers will aim to keep the max possible stress well below failure, but safety factors differ between industries.
40
So we've seen a stiff material and a flexible material.
41
Now let's look at a material in between.
42
This material can be described as tuff and ductile.
43
Tuff simply means the material can absorb a lot of energy without breaking.
44
The area under the graph here defines how much energy is absorbed.
45
Ductile means it deforms under pressure.
46
The two previous materials could also be considered ductile.
47
Springsteel is a tough and ductile material with a high yield strength which is why it is used in springs.
48
Springs need to absorb energy without permanently deforming.
49
The opposite of ductile is brittle.
50
A brittle material is a material that breaks with very little deformation.
51
Glass, ceramics and cast iron all fall into this category.
52
You can actually tell if a material is brittle or ductile by examining the fracture surface after they have broken.
53
A ductile material will have this characteristic cup and cone fracture surface, whereas brittle fractures have granular flat looking fracture surfaces.
54
Some materials can go from ductile to brittle when their temperatures are lowered.
55
This was actually a massive problem during World War 2 with the Liberty ship.
56
Several Several of these ships literally broke in half with no warning, including the SS John P.
57
Gaines, which broke in half in the frigid waters of the Bering Sea.
58
It was later discovered that the grade of steel being used became brittle at lower temperatures.
59
This problem was made worse by the stress concentration at the hatches, which you learned about in my first video, Why are plane windows round?
60
This embrittlement is also thought to have contributed to the fracture of the titanic's hull.
61
The final material property I want to talk about is hardness.
62
It is directly related to the stiffness and yield strength of the material, but it is used to describe how difficult it is to dent, scratch and abrade materials.
63
One way this material property is measured is with the Rockwell hardness test.
64
This test involves three steps.
65
First a minor load is applied to the material by an indenter.
66
This establishes a zero point.
67
For the second step, a major load is then added, which indents the material.
68
And for the final step, the major load is removed, while maintaining the initial load.
69
The difference in depth between the first and third step is then used to calculate the hardness of the material.
70
Diamond is a very hard material, which is why it is used in cutting tools.
71
One of the fantastic properties of steel is its ability to be heat treated, to have its hardness tailored in different areas.
72
For example, with swords you want your cutting edge to be hard but the core of the blade to be ductile.
73
This means the sword can bend under pressure without breaking, while the cutting edge can resist damage.
74
As always, thanks for watching.
75
I wouldn't have the opportunity to make videos like this without sponsors like Lumart.
76
Lumart is a new way to get college done quickly, from the university or college you choose for a lot less money.
77
I was lucky enough to get an education in Ireland for pretty much free, but this is not a luxury many people have.
78
In the US, the cost of getting a higher degree from a university is prohibitively expensive.
79
And the Lumerit Scholar program is out to change that.
80
Whether you are aspiring to go to college, or you are already there, Lumerit can allow you to complete up to 3 years of college for $4,000 or less per year,
81
and allow you to take classes from anywhere in the world.
82
So how does it work?
83
A Lumerit counselor will help you plan out your college path, getting credits from schools that are guaranteed to transfer to your target school.
84
Go to lumertscholar.com forward slash realengineering to see how much you can save with Lumert Scholar.
85
They will email you and give you a personalized consultation to help you save thousands on your education.
📺 Mismo canal
✨ Recomendar Video
C11
92 oraciones
How Things Are Made | An Animated Introduction to Manufacturing Processes
Business EnglishUniversity StudentsWorking Adults
C13
28 oraciones
0925.2 financial statements and ratios
Business EnglishUniversity StudentsWorking Adults
C150 oraciones
The Science of Stress: How Does Stress Affect Our Brains and Bodies?
Business EnglishUniversity StudentsWorking Adults
C11
103 oraciones
Hard Fasteners
Business EnglishUniversity StudentsWorking Adults
C15
188 oraciones
Fix your Trousers Fitting Issues | Body Specific Adjustments (Part 1)
Business EnglishUniversity StudentsWorking Adults
C112
47 oraciones
Essence of linear algebra preview
American AccentBusiness EnglishUniversity StudentsWorking Adults
C12
32 oraciones
Equilibrium of Rigid Bodies (2D - Coplanar Forces) | Mechanics Statics | (Solved examples)
Business EnglishUniversity StudentsWorking Adults
C12
131 oraciones
Unit Conversion & Significant Figures: Crash Course Chemistry #2
Business EnglishUniversity StudentsWorking Adults
C11
132 oraciones
Video
Business EnglishUniversity StudentsWorking Adults
C124 oraciones
Sofeast PCB Video Series Introduction
Business EnglishUniversity StudentsWorking Adults
C1117 oraciones
Anatomy & Physiology: The Ultimate Beginner's Guide | Dr. Bee's Tutorials
Business EnglishUniversity StudentsWorking Adults
C14
139 oraciones
Introduction 2, Why "Portland" cement
Business EnglishUniversity StudentsWorking Adults
Vocabulario y notas de pronunciación para esta lección
Esta lección de conversación de nivel C1 se basa en el vídeo “Material Properties 101”. Las palabras que más se repiten: material, stress, ductile, brittle, strength. Este vídeo tiene 85 frases y 1264 palabras para practicar shadowing. La parte hablada dura 6:06. El hablante habla rápido, unas 207 palabras por minuto, así que espera sonidos enlazados y reducidos. El 82 % de las palabras está entre las 3.000 más comunes del inglés; conviene repasar el resto antes de empezar.
Vocabulario clave de este vídeo
Las 15 palabras más avanzadas del vídeo, con su pronunciación y significado:
| Palabra | Pronunciación | Significado |
|---|---|---|
| distress sustantivo | /dɪˈstɹɛs/ | distrés, distress |
| brittle adjetivo | /ˈbɹɪtəl/ | frágil, quebradizo |
| deformation sustantivo | /ˌdɛfəˈmeɪʃən/ | deformación |
| fracture sustantivo | /ˈfɹæk.t͡ʃʰəː/ | fractura |
| deform verbo | /dəˈfɔɹm/ | deformar, desformar |
| hardness sustantivo | /ˈhɑɹdnəs/ | dureza, duricia (disused) |
| modulus sustantivo | /ˈmɑdʒələs/ | módulo |
| tensile adjetivo | /ˈtɛn.sɪl/ | tensil, tensional |
| stiff adjetivo | /stɪf/ | rígido, duro |
| graph sustantivo | /ɡɹæf/ | gráfico, gráfica |
| elastic adjetivo | /ə-/ | elástico |
| absorb verbo | /æbˈsɔɹb/ | absorber |
| tuff sustantivo | /tʌf/ | toba, tufo |
| slope sustantivo | /sloʊp/ | pendiente, cuesta |
| axis sustantivo | /ˈæksɪs/ | eje |
Phrasal verbs que vas a escuchar
| Palabra | Significado |
|---|---|
| back up verbo | retroceder, ciar |
Gramática en este vídeo
Las estructuras que más usa el hablante, con las palabras exactas del vídeo:
| Estructura | En el vídeo |
|---|---|
| Voz pasiva be + participio pasado — importa lo que ocurre, no quién lo hace | will be uploaded · is defined · is found |
| Present perfect have/has + participio pasado — una acción pasada que sigue importando ahora | has occurred · we've seen · have broken |
| Oraciones de relativo who / which + oración — información extra sobre una persona o cosa | stress, which is · strength which is · material, which is |
Pronunciación a tener en cuenta
El hablante usa 3 contracciones y formas reducidas, como I'll, we've, wouldn't. Dilas en su forma corta, tal como las oyes.
- Los sonidos de “sh” y “zh”: deformation /ˌdɛfəˈmeɪʃən/, deflection /dəˈflɛkʃən/, sectional /ˈsɛkʃənəl/, consultation /ˌkɑnsəlˈteɪʃən/
- Palabras largas — cuida el acento: deformation /ˌdɛfəˈmeɪʃən/, allowable /əˈlaʊ.əbəl/, personalize /ˈpɜː.sə.nə.laɪz/, characteristic /ˌkæɹ(ə)ktəˈɹɪstɪk/, consultation /ˌkɑnsəlˈteɪʃən/
Sonidos difíciles para hispanohablantes:
- s + consonante al inicio — sin añadir una “e” delante: stiff /stɪf/, slope /sloʊp/, steep /stiːp/, sponsor /ˈspɒn.səː/
- /dʒ/ — no es la “y” ni la “ch”: modulus /ˈmɑdʒələs/, frigid /ˈfɹɪd͡ʒɪd/, hugely /ˈhjuːd͡ʒli/
- /h/ — una aspiración suave, no la “j”: hardness /ˈhɑɹdnəs/, hugely /ˈhjuːd͡ʒli/, hatch /hæt͡ʃ/, hull /hʌl/
Cómo practicar con este vídeo
- Escucha el vídeo entero una vez sin hablar y anota las palabras que no conoces.
- Empieza a velocidad 0,75×, haz shadowing frase por frase y vuelve a la velocidad normal cuando te resulte fácil.
- Grábate y compara con el original, prestando atención a palabras como distress, brittle, deformation.
¿Qué es la Técnica de Shadowing?
Shadowing es una técnica de aprendizaje de idiomas respaldada por la ciencia, desarrollada originalmente para la formación de intérpretes profesionales y popularizada por el políglota Dr. Alexander Arguelles. El método es simple pero poderoso: escuchas audio en inglés nativo y lo repites en voz alta de inmediato, como una sombra que sigue al hablante con solo 1-2 segundos de retraso. A diferencia de la escucha pasiva o los ejercicios de gramática, el shadowing obliga a tu cerebro y músculos de la boca a procesar y reproducir simultáneamente patrones de habla reales. Las investigaciones muestran que mejora significativamente la precisión de la pronunciación, la entonación, el ritmo, el habla conectada, la comprensión auditiva y la fluidez al hablar, convirtiéndola en una de las metodologías más efectivas para la preparación del IELTS Speaking y la comunicación en inglés en el mundo real.