Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
(OP)
Say you are designing a column using Direct Analysis Method (DAM). You are required to reduce the flexural stiffness, EI, of your column member by 0.8, which will result in a horizontal larger displacement. When you calculate the elastic critical buckling stress, Fe, for that member using Aisc Eq. E3-4, would you factor Fe by 0.8 since it contains the variable E?






RE: Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
RE: Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
It states that the reduced stiffness and notional load requirements only pertain to analyses for strength limit states. They do not apply to analyses of serviceability conditions of excessive deflections, vibration, etc.
They then continue stating that the reduced E is only to be applied for the second-order analysis. The elastic modulus should not be reduced in nominal strength equations that include E. The net effect is to amplify the second-order forces such that they are closer to the actual internal forces in the structure.
Maine EIT, Civil/Structural.
RE: Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
RE: Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
Maine EIT, Civil/Structural.
RE: Reduced Flexural Stiffness for Direct Analysis Method Affecting Elastic Critical Bucking Stress
Maine EIT, Civil/Structural.