Elastic Properties and Young Modulus
To describe elastic properties of linear objects like wires, rods, or columns which are stretched or compressed, a convenient parameter is the ratio of the stress to the strain, a parameter called the "Young's modulus" or " Modulus of Elasticity" of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material.
| Material |
Young's Modulus (Modulus of Elasticity)
- E - |
Ultimate Tensile Strength
- Su -
(106 N/m2, MPa) |
Yield Strength
- Sy -
(106 N/m2, MPa) |
| (106 psi) |
(109 N/m2, GPa ) |
| ABS plastics |
|
2.3 |
40 |
|
| Acrylic |
|
3.2 |
70 |
|
| Aluminum |
10.0 |
69 |
110 |
95 |
| Antimony |
11.3 |
|
|
|
| Beryllium |
42 |
|
|
|
| Bismuth |
4.6 |
|
|
|
| Bone |
|
9 |
170
(compression) |
|
| Boron |
|
|
|
3100 |
| Brass |
|
100 - 125 |
250 |
|
| Bronzes |
|
100 - 125 |
|
|
| Cadmium |
4.6 |
|
|
|
| Carbon Fiber Reinforced Plastic |
|
150 |
|
|
| Cast Iron 4.5% C, ASTM A-48 |
|
|
170 |
|
| Chromium |
36 |
|
|
|
| Cobalt |
30 |
|
|
|
| Concrete, High Strength (compression) |
|
30 |
40
(compression) |
|
| Copper |
17 |
|
220 |
70 |
| Diamond |
|
1,050 - 1,200 |
|
|
| Douglas fir Wood |
|
13 |
50
(compression) |
|
| Glass |
|
50 - 90 |
50
(compression) |
|
| Gold |
10.8 |
|
|
|
| Iridium |
75 |
|
|
|
| Iron |
28.5 |
|
|
|
| Lead |
2.0 |
|
|
|
| Magnesium |
6.4 |
45 |
|
|
| Manganese |
23 |
|
|
|
| Marble |
|
|
15 |
|
| Mercury |
|
|
|
|
| Molybdenum |
40 |
|
|
|
| Nickel |
31 |
|
|
|
| Niobium (Columbium) |
15 |
|
|
|
| Nylon |
|
2 - 4 |
75 |
45 |
| Oak Wood (along grain) |
|
11 |
|
|
| Osmium |
80 |
|
|
|
| Pine Wood |
|
|
40 |
|
| Platinum |
21.3 |
|
|
|
| Plutonium |
14 |
|
|
|
| Polycarbonate |
|
2.6 |
70 |
|
| Polyethylene HDPE |
|
0.8 |
15 |
|
| Polyethylene Terephthalate PET |
|
2 - 2.7 |
55 |
|
| Polyimide |
|
2.5 |
85 |
|
| Polypropylene |
|
1.5 - 2 |
40 |
|
| Polystyrene |
|
3 - 3.5 |
40 |
|
| Potassium |
|
|
|
|
| Rhodium |
42 |
|
|
|
| Rubber |
|
0.01 - 0.1 |
|
|
| Selenium |
8.4 |
|
|
|
| Silicon |
16 |
|
|
|
| Silicon Carbide |
|
450 |
|
3440 |
| Silver |
10.5 |
|
|
|
| Sodium |
|
|
|
|
| Stainless Steel, AISI 302 |
|
|
860 |
502 |
| Structural Steel, ASTM-A36 |
|
200 |
400 |
250 |
| Steel, High Strength Alloy ASTM A-514 |
|
|
760 |
690 |
| Tantalum |
27 |
|
|
|
| Thorium |
8.5 |
|
|
|
| Titanium |
16 |
|
|
|
| Titanium Alloy |
|
105 - 120 |
900 |
730 |
| Tungsten |
|
400 - 410 |
|
|
| Tungsten Carbide |
|
450 - 650 |
|
|
| Uranium |
24 |
|
|
|
| Vanadium |
19 |
|
|
|
| Wrought Iron |
|
190 - 210 |
|
|
| Zinc |
12 |
|
|
|
- 1 N/m2 = 1x10-6 N/mm2 = 1 Pa = 1.4504x10-4 psi
- 1 psi (lb/in2) = 144 psf (lbf/ft2) = 6,894.8 Pa (N/m2) = 6.895x10-3 N/mm2
Note! Use the pressure unit converter on this page to switch the values to other units.
Strain
Strain can be expressed as
strain = dL / L (1)
where
strain = (m/m) (in/in)
dL = elongation or compression (offset) of the object (m) (in)
L = length of the object (m) (in)
Stress
Stress can be expressed as
stress = F / A (2)
where
stress = (N/m2) (lb/in2, psi)
F = force (N) (lb)
A = area of object (m2) (in2)
Young's modulus or Tensile modulus can be expressed as
E = stress / strain = (F / A) / (dL / L) (3)
where
E = Young's modulus (N/m2) (lb/in2, psi)
Elasticity
Elasticity is a property of an object or material which will restore it to its original shape after distortion.
A spring is an example of an elastic object - when stretched, it exerts a restoring force which tends to bring it back to its original length. This restoring force is in general proportional to the stretch described by Hooke's Law.
Hooke's Law
One of the properties of elasticity is that it takes about twice as much force to stretch a spring twice as far. That linear dependence of displacement upon stretching force is called Hooke's law which can be expressed as
Fs = -k dL (4)
where
Fs = force in the spring (N)
k = spring constant (N/m)
dL = elongation of the spring (m)
Yield strength, or the yield point, is defined in engineering as the amount of stress that a material can undergo before moving from elastic deformation into plastic deformation.
The Ultimate Tensile Strength - UTS - of a material is the limit stress at which the material actually breaks, with sudden release of the stored elastic energy.
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