Function
- Generate the story strength and the results of evaluation of weak story to check capacity irregularity in a spreadsheet format table.
- Story strength is the total strength of seismic-resisting elements sharing the story shear for the direction under consideration. The story strength and the results of evaluation of weak story exhibiting discontinued strength are tabulated.
- When "Story Shear Force Ratio>Consider Story Module" is checked in the "Model/Building/Control Data", accurate shear forces can be obtained for the story having the overlapping Module.
- When Modules are defined in Structure > Building > Story > Define Module button, the Module data is displayed in the first column of the table.
- When the ratios exceed the allowable limit, they appear in red and 'Irregular' is printed in the Remark.
- Table Tool in Gen NX offers a variety of powerful built-in functions. Refer to Usage of Table Tool for detail directions.
Call
From the Main Menu select [Results] tab > [Type : Analysis Result] > [Table] group > [Story Tables] > [Capacity Irregularity Check (Weak Story) Table]
Input
When Modules are not defined
Story : Story number
Level : Elevation of the Story
Story Height : Story (floor to floor) Height
Angle : Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
(ACI is used for the above equation, except for the cases where Japanese and Chinese design codes are selected.)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 0.8, "Regularity" is printed. If the Ratio is between 0.65 and 0.8, "Irregularity" is printed. If it is below 0.65, "Height Limit" is printed.
In the case of Roof, there is no story above the roof. In that case, always "Regularity" is printed.
When Modules are defined
The Module column is generated only when the Modules are defined. Results of evaluation of capacity irregularity are calculated as per the following Note.
Note
"Upper Story Shear Strength" and "Story Shear Strength Ratio" for the story immediately below the top floor of each Module, is displayed as "0" and marked as "Regular".
Module : Module name is defined in Structure > Building > Story > Define Module button
Story : Story number
Level : Elevation of the Story
Story Height : Story (floor to floor) Height
Angle : Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
(ACI is used for the above equation, except for the cases where Japanese and Chinese design codes are selected.)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 0.8, "Regularity" is printed. If the Ratio is between 0.65 and 0.8, "Irregularity" is printed. If it is below 0.65, "Height Limit" is printed.
In the case of Roof, there is no story above the roof. In that case, always "Regularity" is printed.
When Modules are not defined
Story : Story number
Level : Elevation of the Story
Story Height : Story (floor to floor) Height
Angle : Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 0.8, "Regularity" is printed. If the Ratio is between 0.65 and 0.8, "Irregularity" is printed. If it is below 0.65, "Extreme Irregular" is printed.
Note
Capacity Irregularity Check table is provided to check if the story lateral strength is less than 80% of that in the story above but more than or equal to 65%, understanding that the story strength such as the sum of the strengths of all the elements share the story shear for the considered direction. “Extreme Capacity Irregular” will be displayed when the story lateral strength is less than 65% of that in the story above, understanding that the story strength such as the sum of the strengths of all the elements share the story shear for the considered direction.
When Modules are defined
The Module column is generated only when the Modules are defined. Results of evaluation of capacity irregularity are calculated as per the following Note.
Note
"Upper Story Shear Strength" and "Story Shear Strength Ratio" for the story immediately below the top floor of each Module, is displayed as "0" and marked as "Regular".
Module : Module name is defined in Structure > Building > Story > Define Module button
Story : Story number
Level : Elevation of the Story
Story Height : Story (floor to floor) Height
Angle : Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 0.8, "Regularity" is printed. If the Ratio is between 0.65 and 0.8, "Irregularity" is printed. If it is below 0.65, "Extreme Irregular" is printed.
Note
Capacity Irregularity Check table is provided to check if the story lateral strength is less than 80% of that in the story above but more than or equal to 65%, understanding that the story strength such as the sum of the strengths of all the elements share the story shear for the considered direction. “Extreme Capacity Irregular” will be displayed when the story lateral strength is less than 65% of that in the story above, understanding that the story strength such as the sum of the strengths of all the elements share the story shear for the considered direction.
When Modules are not defined
Story: Story number
Level: Elevation of the Story
Story Height: Story (floor to floor) Height
Angle: Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 1.0, "Regularity" is printed otherwise "Irregular" is printed for IS 1893 (2016).
If the Story Shear Strength Ratio exceeds 0.9, "Regularity" is printed otherwise "Irregular" is printed for IS 16700 (2023).
When Modules are defined
The Module column is generated only when the Modules are defined. Results of evaluation of capacity irregularity are calculated as per the following Note.
Note
"Upper Story Shear Strength" and "Story Shear Strength Ratio" for the story immediately below the top floor of each Module, is displayed as "0" and marked as "Regular".
Module: Module name is defined in Structure > Building > Story > Define Module button
Story: Story number
Level: Elevation of the Story
Story Height: Story (floor to floor) Height
Angle: Specify a load direction
1. Story Shear Strength Coefficient
The story strength is calculated in the load direction specified by the user, as well as perpendicular to the load direction. Once Angle1 is entered in "Input angle and press 'Apply' button to change angle", Angle2 automatically becomes Angle1 + 90˚
The following equation is used to calculate Story Shear Strength for vertical elements at a corresponding story.
Story Shear Strength = Σ 0.17λ√(f'c)bd (unit: MPa)
2. Upper Story Shear Strength Coefficient
Story Shear Strength of vertical members immediately above the story in question
3. Story Shear Strength Ratio
Story Shear Strength at a story divided by the Story Shear Strength immediately above the story in question
4. Remarks
If the Story Shear Strength Ratio exceeds 1.0, "Regularity" is printed otherwise "Irregular" is printed for IS 1893 (2016).
If the Story Shear Strength Ratio exceeds 0.9, "Regularity" is printed otherwise "Irregular" is printed for IS 16700 (2023).