stiffness modification factor

[monchie]

Hello,

According to ETABS manual, " The f11, f22 and f12 modifiers are essentially equivalent to modification factors on the thickness of the shell element. The m11, m22 and m12 modifiers are essentially equivalent to modification factors on the thickness3 of the shell element."

To my interpretation, the wall/slab thickness was essentially reduced by the introduction of modifiers. Does it mean that the "self-weight" of the wall or slab was affected as well? Am I correct on this?

 

[Guest262653]

Nope.
These factors are only applied to the respective stiffness. Self-weight is calculated from the element thickness. That's way you have additional factors for mass and weight.

 

[johnbridge231]

These factors only affect the examined stiffness of the shell element regarding its plate and membrane function in the specified direction. Mass and weight are not affected. In order to change the mass or the weight using property modifiers, you can change the related values.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html