Structural Steel Properties for LRFD
Description
Definition of the material properties for a section or beam is a three step process:
- Add the material type (concrete / reinforcing steel / etc.)
- Define a set of properties for that material type (compressive strength etc.)
- Allocate the material properties defined in 1 & 2 to the relevant parts of the section or beam section component.
This form performs the second of these 3 stages for structural steel.
As data is entered the program checks that values are within the expected range for steel. This check will highlight any values in error by a factor of 10 more.
Form Graphic
Field Help
Minimum Yield Strength, Fy
Enter the minimum yield point or minimum yield strength of the structural steel. A warning will be issued if the value entered is unrealistic, but the value will not be rejected.
The default value is 50KSI (345MPa) which is appropriate for High-Strength Low-Alloy steel AASHTO Designation M270M Grade 50, Grade 50S and Grade 50W.
The following values also comply with AASHTO LRFD 9 Table 6.4.1-1: 36KSI; 70KSI; 90KSI; 100KSI.
Modulus of Elasticity
Enter the modulus of elasticity of the steel. The default value of 29,000KSI (200,000MPa) is obtained from A6.4.1 of AASHTO LRFD 9.
As elastic modulus, shear modulus and the Poisson's ratio are related, a change of this value will affect one of the three elasticity parameters, in this case the shear modulus.
Poisson's Ratio, ν
Enter the value for Poisson's ratio. The default value is typical for this type of material. As elastic modulus, shear modulus and the Poisson's ratio are related, a change of this value will affect one of the three elasticity parameters, in this case the shear modulus.
Shear Modulus, G
Enter the shear modulus value. As elastic modulus, shear modulus and the Poisson's ratio are related, a change of this value will affect one of the three elasticity parameters, in this case the Poisson's ratio.
Coefficient of thermal expansion
Enter the coefficient of thermal expansion for use in differential temperature gradient calculations.
The default value is 0.0000117 /°C in accordance with A6.4.1 of AASHTO LRFD 9.
Density
Enter the density of the structural steel.
The default value is 0.49KIP/FT3 (or 76.97 kN/m3 which is equivalent to 7850 kg/m3) as given for steel in Table 3.5.1-1 of AASHTO LRFD 9.
Property name
The program will supply a reference name which should provide a nearly unique identifier to the material property set. This value may be edited to give a more readily recognizable name if required.