Function
- Enter the strength reduction / Design Resistance / Partial Safety factors, which are a form of safety factors to account for the difference between the nominal and real strengths of the materials; the difference in member strengths between the design and manufacturing or construction; and uncertainties related to inaccuracies in the design equations.
Call
From main menu, select [Design] tab > [Type : Steel Design] > [Design Input Data] group > [Design Parameters] > [Strength Reduction / Design Resistance / Partial Safety Factor]
Input
Design Code
Display the selected design code.
Update By Code : Factors are automatically changed to the values specified in the selected design code.
Strength Reduction Factor
It is available when AASHTO, AISC, or Taiwan design code is selected. In AASHTO LRFD Bridge Design Specifications, strength reduction factors are applied to different limit states to account for uncertainties in material properties, construction quality, and loading conditions. These factors ensure a conservative design approach by reducing the nominal resistance of structural components.
For Tension Members
For Yielding in Gross Section (Phi t1)
For Fracture in the Net Section (Phi t2)
For Compression Members (Phi c)
For Flexural Members (Phi b)
For Shear (Phi v)
Resistance Factors
It is available when CSA-S6 or BS5950 design code is selected. In the Canadian Highway Bridge Design Code (CSA-S6), resistance factors are used to ensure safety and account for uncertainties in material properties, construction methods, and loading conditions. These factors are applied to the nominal resistance of materials to determine their design resistance, ensuring a safety margin in structural design.
Partial Safety Factors
It is available when Eurocode3 or IS:800 design code is selected. The partial factors for materials are used to account for the variability in material properties and ensure safety in structural design. These factors are applied to the characteristic strength of materials to determine their design strength.