Introduction
The stiffness modifier determines each structure element’s contribution to the global stiffness matrix. The default value for a beam or column is 1.00, which means that its contribution to the global stiffness matrix will be 100%. For concrete beams, this value is 0.70, meaning that 70% of its contribution to the global stiffness matrix will be considered. For shear wall flexural elements, a value of 0.50 is used as the default. ETABS stiffness modifiers should not be used to model partial wall offsets or out-of-plane column deformations since these effects are already accounted for in reduced stiffness columns.
ETABS stiffness modifiers represent the contribution of each element to the global stiffness matrix.
ETABS stiffness modifiers represent the contribution of each element to the global stiffness matrix. This can be useful for calculating the amount of deflection in a beam or column due to its stiffness, which is used in many design codes and other applications. The default ETABS stiffnesses for beams and columns are 1.00, meaning they contribute 100% to overall strength calculations.
The default stiffness modifier for beams and columns is 1.00.
The default stiffness modifier for beams and columns is 1.00, meaning that these elements’ contribution to the global stiffness matrix is 100%.
The concrete beam stiffness has been adjusted by 0.70 to match the stiffness value of shear wall flexural elements.
For concrete beams, this value is 0.70, meaning that only 70% of its contribution to the global stiffness matrix is considered.
This means that if you have a steel beam, it will have more global stiffness than if it was made out of concrete.
The default values are set to match those found in [GlobalStiffnessModifier], which also uses this method for calculating stiffness modifiers for all other materials besides steel and concrete structures (see section 2).
For shear wall flexural elements, a value of 0.50 is used as the default.
For shear wall flexural elements, a value of 0.50 is used as the default stiffness modifier. This value can be changed by specifying an appropriate multiplier in the stiffness modifier’s settings page.
Modifiers are applied after consideration of eccentricity, axial forces, and P-Delta effects.
Modifiers are applied after consideration of eccentricity, axial forces, and P-Delta effects. The modifiers are applied to the element so that a specified amount reduces the resultant stiffness.
Stiffness modifiers should not be used to model partial wall offsets or out-of-plane column deformations.
ETABS stiffness modifier should not be used to model partial wall offsets or out-of-plane column deformations. It is recommended that you use reduced stiffness columns instead.
Reduced stiffness columns model partial wall offsets and out-of-plane column deformations.
By changing its stiffness modifier, you can change how your structure’s behavior will contribute to its overall stiffness.
By changing its stiffness modifier, you can change how your structure’s behavior will contribute to its overall stiffness. A stiffness modifier is a number that indicates how much a structure’s elasticity affects its overall stiffness, and it can be used with any load or material.
Conclusion
If you have a column and concrete beam pair connected at their center of gravity, and this connection happens to be in the middle of your structure, then you will get a lot less stiffness from your structure than if it were on the side or top. This is because only half of its contribution to the global stiffness matrix will be considered.
