Young's Modulus of Elasticity
Elastic modulus, modulus of linear deformation, coefficient of elasticity, modulus of elasticity
 Young's modulus of elasticity E describes the amount of deflection under load. The modulus of elasticity is placed as a divisor in the deflection formula => the higher the value of the modulus of elasticity, the less the material bends.
The general modulus of elasticity of steel is 21,000 kN/cm2. There are two values used in the literature for the modulus of elasticity, 20,600 and 21,000 kN/cm2. This calculation and the tables use the lower value, which gives a 1% greater deflection. Both values are accurate enough, but it is better to be on the safe side, where the calculation is used in the design.
Young's modulus
When designing a bend, it is determined by the shape of the profile cross-section. This means the same deflection for different steel grades. The strength of the steel is important when achieving a lightweight structure. This is achieved by allowing higher local stresses => greater deflection. The calculation is based on the yield strength guaranteed by the steel manufacturer for special steel and table values for standard steel.
Practical grades of steel are the S235 and S355, which have a wide range of dimensions. Steel product catalogs act as guides for the selection of steel. The elastic limit of steel is between the range of the yield strength and proportionality limit. The limit of proportionality is the first part of a load-elongation curve.
The elongation increases in proportion to an increase in tension. When tension reaches the yield limit, elongation continues from here on more than the increase in tension. Above the elastic limit, it will remain a permanent deformation.
kN/cm2 N/mm2 GPa
Aluminium 7000 70 000 70
Concrete 1 000 - 4 000 10 000 -40 000 10 - 40
Duralumin 7 400 74 000 74
Silver 8000 80 000 80
Invar 14 600 146 000 146
Iridium 15 600 156 000 156
Ice - 4o C 1 000 10 000 10
Cadmium 5 100 51 000 51
Copper 12 000 120 000 120
Glass 7 200 72 000 72
Natural rubber (caoutchouc) 5 50 0,05
Brass and Bronze 10 300 - 12 400 103 00 - 124 00 100
Nylon 200 - 400 2 000 - 4 000 2 - 4
Steel 21 000 210 000 211
Titanium 10 500 - 12 000 105 000 - 120 000 105 - 120
Diamond 105 000 - 120 000 1 050 000 - 1 200 000 1050 - 1200
Oak along the grains 1 100 11 000 11
Tungsten 40 000 400 000 400
Tungsten carbide 45 000 - 65 000 450 000 - 650 000 450 - 650
1 Pa = N / m2
Finally
- Of stronger material manufactured part can be loaded with a greater force.
- Strength does not have stiffness => another increase, also another grows. As a result of this analysis has a mathematical possibility, while maintaining the proportionality of load conditions, and comparable materials.
- The modulus of elasticity is a divisor in the formula => to reduce the deflection, must choose the larger cross-section of the same material or a material change to a higher elastic modulus.
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