All Questions
Tagged with material-science elasticity
119
questions
4
votes
2
answers
223
views
What is a general definition of bulk modulus?
For a perfectly elastic body, Bulk modulus always remains constant and is defined as,
$$B=-V_i \frac{\Delta P}{\Delta V} \tag{1}$$
Which means,
$$B \left(\frac{V_f -V_i}{V_i}\right)= -(P_f-P_i)$$
But, ...
- 261
0
votes
0
answers
41
views
Justification for Statements on Beam Deflection
I am teaching students at a high school about bending of a beam (the beam is clamped at one end and then an applied force acts downwards close to the end of the beam to bend it).
I thought that it did ...
- 1,410
0
votes
0
answers
44
views
Question about the elasticity matrix in metals
The most general anisotropic linear elastic material has 21 elastic constants. I am working with an HCP material and I found that it has 5 independent elastic constants. I am programming a subroutine ...
0
votes
1
answer
61
views
How would I understand Hysteresis from scratch? [closed]
I wanted to learn about Hysteresis and I know the basic undergraduate level of 'Mechanical properties of matter".
Can anyone please help?
1
vote
1
answer
251
views
Equations of motion for two masses connected by the Kelvin-Voigt Model
I have a system where two particles $x_1$ and $x_2$ in one dimension are connected by a spring and a dash in parallel. This is analogous to the Kelvin-Voigt model for viscoelastic materials. The two ...
- 121
2
votes
2
answers
99
views
How does restoring shear forces arise (in elastic conditions)? Do they arise from central forces or not?
When you apply a shear force onto a solid piece of material (say a block on a surface or a cantilever
beam with a load) that creates shear stress in the elastic regime, there is a restoring force that ...
- 8,640
1
vote
1
answer
91
views
How to derive properly the stress-strain relation of an hyperelastic material?
I'm trying to implement a Yeoh hyperelastic model for a FEM simulation. The program requires a function that returns the second Piola-Kirchhoff stress tensor $\mathbf{S}$, with the Green-Lagrange ...
- 11
0
votes
0
answers
46
views
Since when has the formula $I = \frac{b h^3}{12}$ (second moment of area) has been discovered and applied in building construction?
A question about history of physics: since when and by who has the formula for the second moment of area
$$I = \frac{b h^3}{12}$$
been discovered? When has it started being applied in building ...
- 183
4
votes
2
answers
452
views
Prove that an isotropic substance has only two elastic constants
I've been following the derivation from Ch. II-31 of Feynman's Lectures, and there is a bit that I don't understand. We start from the relation between the strain $T_{ij}$ and the stress $S_{ij}$, $$...
- 163
0
votes
0
answers
58
views
What are the exact conditions for 1D elastic collisions? Is there a list for characterizing when elastic collisions occur?
We know there are elastic, inelastic, and partially elastic collisions. In a fully elastic collision, both momentum and kinetic energy are fully conserved. However, that tells us nothing for which ...
- 8,640
1
vote
1
answer
199
views
What is the microstructural explanation for the high Poisson's ratio of rubber?
Natural rubber has the highest quoted Poisson's ratio I've seen for a real material, usually given as 0.4999. This obviously makes intuitive sense when you think about the behaviour of rubber, and I'...
0
votes
1
answer
2k
views
What is the difference between elasticity and stiffness? [closed]
Modulus of elasticity indicates Elasticity(E) but stiffness(specifically in case of axial deformations) is given as EA/L where A is area and L is length of body. These expressions led me to believe ...
- 27
2
votes
2
answers
512
views
How to obtain the equivalent Young Modulus in Hertzian contact?
I would like to understand why there's a $\nu²$ in the expression of the equivalent Young modulus in the Hertzian contact theory.
Here's a common expression for an elastic sphere crushed on a rigid ...
- 21
1
vote
0
answers
76
views
If you were to (somehow) compress a golf ball so it fits into the radius of a grain of sand, how much energy would be released when it "sprung" back? [closed]
I'm curious approximately how much energy would be stored in the repulsion (both classical electrostatic, and any Pauli-type quantum effects) between the electrons if the "space" between the ...
- 119
2
votes
0
answers
90
views
Why does a spring work the way it does?
I am wondering if anyone can explain what exactly makes the shape of a spring so good at creating something so elastic and good at converting between kinetic and potential energy.
The metal itself isn'...
- 8,640