Hello, let me answer your question about what Young's modulus is and what Young's modulus is. I believe many friends still don't know. Now let's have a look!
1, Young's modulus is elastic modulus, which is a concept in material mechanics.
2. For linear elastic materials, the formula σ = E ε holds, where σ is the normal stress, ε is the positive strain, and E is the elastic modulus, which is a constant related to the material.
3. Thomas Young (1773 ~ 1829) is a British physicist.
4. Born in Milverton.
As early as childhood, he showed extraordinary talent and amazing memory.
When I was 6 or 9 years old, I was able to make some physical instruments by myself.
7./kloc-at the age of 0/4, he mastered Newton's differential method and many languages such as Latin, Greek, French, Italian, Hebrew, Persian and Arabic.
8. Later, I studied medicine at St. bartholomew College in London.
At the age of 9.2 1, he became a member of the royal society with his first medical paper.
10. Since then, he has been engaged in the research of physiological optics with surgeon john hunter in London.
1 1. He studied in Edinburgh, Cambridge and G? ttingen.
12, Yang mainly engaged in the research of physics in his later years.
13, 180 1 ~ 1804 are professors of the royal society.
14, 1802 ~ 1828 served as secretary of the royal society.
15, also an academician of the Paris Academy of Sciences.
Yang is one of the founders of wave optics.
17, during my further study in Germany, I doubted Newton's theory of light particles.
18, and put forward the topic of sound and language in Dr. Gottingen's thesis. According to the research results of optics, it is proved that sound and light are both waves, and different colors of light and different frequencies of sound are different waves.
In 19 and 1800, the experiment and research summary of sound and light systematically discussed the wave theory of light, challenged Newton's particle theory of light, and thought that it was more effective to explain the propagation speed of strong light as weak light. It is pointed out that wave theory can also prove the birefringence of Iceland spar, which can not be explained by particle theory.
In 20 years, 180 1 year, a famous optical interference experiment was carried out, in which a small hole was irradiated with strong light and used as a point light source to emit spherical waves.
2 1. Two other holes are placed at a certain distance from the holes, and the spherical wave emitted by the first hole is divided into two small parts as coherent light sources.
22. So there is interference in the area where the light waves emitted by these two holes meet.
23. Light and dark interference patterns can be obtained on the screen behind the double holes.
24. Later, it was found that a brighter interferogram could be obtained by using double slits instead of double holes.
25. In 1803, the word "interference" was introduced, and an attempt was made to explain the diffraction caused by light, and to link interference with diffraction.
26. It is proved that when light is reflected on dense medium, half-wave loss will occur.
27. By measuring the wavelengths of different colors, the values obtained are 0.7 micron for red light and 0.42 micron for purple light.
28, 1807, put forward the following view: the difference between light and radiant heat is only wavelength.
18 17. When he learned about Fresnel's and arago's experiments on polarized light interference, he proposed that light is a shear wave.
30. Before that, the application of optical theory in medicine laid the foundation of physiological optics.
In 3 1 and 1793, it is proposed to adjust the observation of objects at different distances by changing the curvature of the eyeball lens, which is the earliest explanation of the optical principle of the eye.
32, 1803, it is proposed that people distinguish colors because there are several different structures on the retina that feel red, green and purple light respectively, which can explain the cause of color blindness.
33. The principle of three primary colors is established, and it is believed that all colors are composed of red, green and blue in three different proportions. This principle has become the basis of modern painting, printing, television and photography.
34. In the field of material mechanics, shear deformation is studied and it is considered that shear stress is an elastic deformation.
35, 1807, put forward the definition of elastic modulus, so the elastic modulus is called Young's modulus.