A509.3.2 Modeling of Building Components

Component initial stiffness shall be represented by a secant value defined by the effective yield point of the component. The effective initial stiffness shall be calculated using principles of mechanics, with due consideration of the effects of tensile cracking and compression strain.

Exception: Component effective initial stiffness may be calculated using the approximate values shown in Table A508.1.

The strength of building components shall be calculated using the procedures outlined in the appropriate section of the building code.

Exception: Component properties may be calculated using the principles of mechanics as verified by experimental results.

The deformability of building components shall be obtained from nonlinear load-deformation relationships that are appropriate for the component being considered. The nonlinear load-deformation relationship shall include information on the plastic deformation capacity at which lateral strength degrades, the plastic deformation capacity at which gravity-load resistance degrades, and the residual strength of the component after strength degradation.

The nonlinear load-deformation relationships of building components shall be determined from nonlinear analyses based on the principles of mechanics, experimental data or established values published in technical literature, as approved by the building official.