Physical quantities are tensors - What is a tensor??

This presentation explains what are tensors, what are its special types and examples. At the end stress and strain tensorts are shown.

Category:

Science & Technology

Tags:

• tensor
• stress
• strain
• matrix
• vector
• scalar
• material mechanics

[EinsteinInSkirt]

These numbers are just examples chosen by me. Each one of the twenty numbers listed in the slide at 1:45 is a value of the tensor of 3. order. If still do not understand let me know: einsteininskirt@gmx.de.

[mzallocc]

At 4:10, you have "simplification using: T13 = T13 ..."

Should this be T13 = T31 ?

[EinsteinInSkirt]

@mzallocc Yes, it should be: tau 13 = tau 31. Thank you. 

[EinsteinInSkirt]

I will answer other posts soon :) thanks for comments.

[jorge91785]

i don´t understand



[EinsteinInSkirt]

@jorge91785 Now I am sad. What exactly you do not understand?

[moonlight271]

To best explain a concept it is best to start with something that everyone understands and work from there . . . not the reverse. Eg. A scalar quantity (zeroth order tensor) such as temperature or mass needs only one number to describe it. A vector quantity (1st order tensor) such as velocity needs two numbers (magnitude and direction) and a third order tensor will presumably require 3 numbers to describe it and so on. But what is a clear example of a second order tensor quantity please?

[JesusAlbertoPinto]

@supertren Nope, a vector is a tensor of first order.

[emachines34]

I am very confused about how to find value of the tensor, 1:45.

How do you arrive at the value T(111)=1 and T(123)=12.34?

Please help

[analyitic1]

thanks, a really good video. Basically a tensor is a generalisation of a matrix. Just like the inner product is a generalisation of the dot product. For example, an inner product is the usual dot product in euclidean space and can be something else in another vector space (as long as it satisfies the relevant axioms). Here, a tensor plays the same kind of role, in the sense that it can be a matrix (tensor of order 2) or a vector (tensor of order 1) or a scalar (tensor of order 0) etc...

[Soltaire7Life]

really thanx for ur video... but doubt for me remains... :S