Function
- Enter the strength reduction 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; uncertainties related to inaccuracies in the design equations; and the ductility and importance of the member.
Call
From the main menu, select [Design] tab > [Type : RC Design] > [Design Input Data] group > [Design Parameters] > [Strength Reduction Factor]
From the main menu, select [Design] tab > [Type : RC Design] > [Design Input Data] group > [Design Parameters] > [Resistance Factor]
From the main menu, select [Design] tab > [Type : RC Design] > [Design Input Data] group > [Design Parameters] > [Partial Safety Factors for Material Properties]
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 Factors
Enter the strength reduction factor in each field. It is available when AASHTO-LRFD or ACI 318 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 Flexure (Phi_B) : Strength reduction factor for pure flexure or flexure + axial tension
For Axial Tension (Phi_T) : Strength reduction factor for axial tension
For Axial Compression, and Axial Compression and Bending
- Spirally Reinforced Column (Phi_C1) : Strength reduction factor for spirally reinforced columns subjected to axial compression or flexure + axial compression
- Other Reinforced (Tied) Column (Phi_C2) : Strength reduction factor for tied columns subjected to axial compression or flexure + axial compression
For Shear (Phi_V) : Strength reduction factor for shear
When the strength reduction factors are not entered, the strength reduction factors specified in the current design code are used.
Resistance Factors
It is available when CSA-S6 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 Eurocode 2, BS 5400-4, IRC:112, IS456 or IRS 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.