Function
- Define the plastic hinge data to be used in Pushover analysis.
Note
Hinge properties such as yield strength are calculated based on the specified design code in Design>Concrete/Steel Design Parameter>Design code.
Call
From the Main Menu select [Pushover] tab > [Properties] group > [Hinge Properties] > [Define Pushover Hinge Properties]
Input
Click the Add button to define plastic hinge information in the dialog box below. Click the Modify/Show button to confirm or modify and the Delete button to delete the data entry. Select the pushover hinge to be copied in the dialog box and click the Copy button.
After defining the hinge type and assigning it to the selected members, check on the Show Generated Hinges in the Define Pushover Hinge Data dialog box to check the automatically calculated hinge data by the section information. Select the hinge data to be checked and click the Modify/Show button to prompt the Add/Modify Hinge Data Type dialog box in which the Properites... button is clicked to check the hinge data. Corrections to the assigned hinge data are not permitted here.
Note 1
When members are assigned hinge properties, inherent titles are assigned to the automatically generated hinge data. For example, "B1-PMM" represents:
B: Hinge assigned to a beam element
1: Sequential number assigned to by element types
Beam: Assigned hinge type (Beam, Column, PMM)
Note 2
Hinge properties of each element are automatically generated according to the sectional information. For reinforced concrete members, reinforcing steel must be pre-determined through the design feature in Gen. Reinforcing steel data for the relevant sections must be provided in Modify Beam (Column, Brace & Wall) Section Data of Concrete Design Parameter. If the automatic design feature for reinforced concrete members (Concrete Code Design) is used, you are required to enter the reinforcing data using the Update Rebar button in the Design Result dialog box for each element.
Note 3
Strength calculation method for Value Type Steel Section
1. Sectional information such as Area, Asy, Asz, Cym, Cyp, Czm, Czp, Zyy, and Zzz cannot be 0 for auto-calculation (Zyy, Zzz are new items added in Value Type and can be checked in Model > property > Section).
2. Hinge strength is calculated for P, My-Mz, Vy-Vz, and PMM.
3. For Yielding, the PM-Curve is generated on the basis of Pc (compressive strength), Pt (tensile strength), and M0 (flexural strength at P=0, or Fy×yy, Fy×zz).
4. For Ultimate, the PM-Curve is generated on the basis of Pc (compressive strength), Pt (tensile strength), and M0 (flexural strength at P=0, or Fy×Zyy, Fy×zz).
Hinge Properties Type Name
Define names of plastic hinge properties.
Description
State a brief description related to the pushover hinge properties.
Element Type
Specify the type of element.
Beam/Column : Beam or Column element
Wall : Wall element
Truss : Truss element
General Link : Spring which can be defined at Boundary > Link > General Link > General Link Properties
Point Spring Support : Point Spring Support
Wall Type
Specify the type of wall element.
Membrane : Only in-plane plasticity is considered
Plate : Both in-plane and out-of-plane plasticity are considered
Material Type
Specify the type of material used to the corresponding element.
RC / SRC (encased) : RC or SRC (Steel-encased concrete type)
Steel / SRC (filled) : Steel or SRC (Concrete-filled steel tube type)
Masonry : Masonry type
Definition
Specify the load-deformation relationship of the flexural member.
Moment-Rotation (M-θ)
Moment-Curvature (M-φ Lumped)
Consider Hinge Length : Check on to assign pushover hinge to the specified hinge length.
Integration Point : Select the integration point location to End or Center of the hinge length.
Fig. When Integration Point is “End”
Fig. When Integration Point is “Center”
Moment-Curvature (M-φ Distributed)
Pier Type : For vertical members in the masonry material type. Hinge properties are defined in terms of moment-rotation relationship for a members section.
Spandrel Type : For horizontal members in the masonry material type. Hinge properties are defined in terms of moment-rotation relationship for a members section.
Hinge Type
Skeleton Model : Hinge Model idealized in a straight line.
Fiber Model : Hinge Model with curved shape through FEA analysis
* Fiber Model can be selected only under “Moment-Curvature” type
Interaction Type
None : Axial force and biaxial moments are uncoupled from each other.
P-M in Status Determination : Coupled axial force-uniaxial moment behavior is reflected by calculating the flexural yield strength of a hinge considering the effect of axial force.
P-M-M in Status Determination : Coupled axial force-biaxial moment behavior is reflected by calculating the flexural yield strength of a hinge considering the effect of axial force.
Element Selection
Selected Elements in View : Select an elements to ignore an initial load during pushover analysis.
Import “Ignore Element for Load Case” Data : Apply “Ignore Elements for Load Case” data.
- Load Case Name : select a target load case
- The ... Button : check and modify “Ignore Elements for Load Case” data.
* “Ignore Elements for Load Case” “ can be called from ” Boundary > Etc. > Ignore Elements for Load Case”
Component Properties
Fx, Fy, Fz, Mx, My, Mz : Check on the degree of freedom to be assigned to the plastic hinge type.
Hinge Location : Specify the hinge location within the corresponding element.
Number of Section : Specify the number of integration points when Definition is selected as 'Moment-Curvature (M-φ Distributed)'.
Skeleton Curve : Specify the skeleton curve.
Hinge Length (Lv) : Specify the ratio of moment / shear at the end section to calculate total chord rotation capacity as per EN 1998-3:2004, Annex A.3.1. This function becomes activated only when Eurocode8:2004 is selected.
Note 1
The skeleton curves available are as follows:
1. Bilinear Type (or Slip Bilinear Type)
2. Trilinear Type (or Slip Trilinear Type).
3. FEMA Type
4. Eurocode8:2004
Yield Rotation Analysis Option
Fig. Dy Update
Fig. Du Update
- Slip Bilinear Type or Slip Trilinear Type is activated when the Element Type is defined as 'Truss' or 'General Link'.
Note 2
The Multi-Linear Type is applicable for both the load control and the displacement control methods and both FEMA and Eurocode 8 type is applicable only for the displacement control method.
The Properties... Button
Enter the relevant hinge properties in the following dialog box:
Input Method
Auto-Calculation : The corresponding yield strength is automatically calculated based on the design code.
Note
Following definitions are required for Auto-Calculation.
1. Design Code
2. Material and section properties defined from the standards
3. Rebar data for RC members
User Input : All the input data are user-defined parameters.
Input Type
Strength - Stiffness Reduction Ratio : Define the Skeleton Curve using the yield strength and the stiffness reduction ratio.
Strength - Yield Deformation : Define the Skeleton Curve using the yield strength and the yield deformation defined by the user.
Note
1. Strength - Yield Deformation option is activated when the Input Method is set to User Input.
2. Yield Deformation is changed depending on the component. (Fx : yield deformation, Fy & Fz : yield strain, Mx & My & Mz : yield rotation angle)
Value Type of I-End & J-End
Symmetric : Select if rebar arrangement between i-end and j-end are symmetrical.
Asymmetric : Select if rebar arrangement between i-end and j-end are asymmetrical.
Note
Value Type of I-End & J-End option is activated when the hinge type is defined as Moment-Rotation (M-Θ) or Moment-Curvature (M-φ Lumped) and User Input option is selected. The asymmetrical yield strengths between I-end and J-end are automatically reflected when input method is set to Auto-Calculation.
Type
Symmetric : Select if the hinge properties are symmetric in the positive and negative directions.
Asymmetric : Select if the hinge properties are asymmetric in the positive and negative directions.
Yield Strength
The values are automatically calculated using the section information if Input Method is set to Auto-Calculation. Or the user may enter the values of Yield Moment and Yield Rotation manually if Input Method is User-Input.
P1: 1st Yield Strength
It represents the cracking strength of concrete or the member force of a structural steel member at the time the top or bottom fiber starts yielding.
P2 : 2nd Yield Strength
It represents the starting point of concrete rupture or yielding of reinforcing steel. In the case of structural steel, it represents the member force at which an entire member starts yielding.
Note
The values for the 2nd My must be greater than those for the 1st My (Mcr).
Stiffness Reduction Ratio
Use Value of Global Control Data : Stiffness reduction ratio defined in Pushover Global Control dialog is used.
User Defined : User defined stiffness reduction ratio is used.
Initial Stiffness
6EI/L, 3EI/L, 2EI/L : It is activated when Definition is defined as Moment - Rotation (M-θ).
User : Defined by the user
Elastic Stiffness：Elastic stiffness is used for the initial stiffness.
Initial Gap
Enter the initial gap in tension and compression when element type is Truss or General Link for the Slip Bilinear Type or Slip Trilinear Type of skeleton curve.
Input Method
Auto-Calculation : The corresponding yield strength is automatically calculated based on the design code.
Note
Following definitions are required for Auto-Calculation.
1. Design Code
2. Material and section properties defined from the standards
3. Rebar data for RC members
User Input : All the input data are user-defined parameters.
Value Type of I-End & J-End
Symmetric : Select if rebar arrangement between i-end and j-end are symmetrical.
Asymmetric : Select if rebar arrangement between i-end and j-end are asymmetrical.
Note
Value Type of I-End & J-End option is activated when the hinge type is defined as Moment-Rotation (M-Θ) or Moment-Curvature (M-φ Lumped) and User Input option is selected. The asymmetrical yield strengths between I-end and J-end are automatically reflected when input method is set to Auto-Calculation.
Type
Symmetric : Select if the hinge properties are symmetric in the positive and negative directions.
Asymmetric : Select if the hinge properties are asymmetric in the positive and negative directions.
Yield Strength (MY)
The values are automatically calculated using the section information if Input Method is set to Auto-Calculation. Or the user may enter the values of Yield Moment manually if Input Method is set to User-Input. The coordinate system follows the Element local Coordinate System.
Yield Rotation (DY)
User Defined
The values are automatically calculated using the section information if this option is checked off. Or the user may enter the values of Yield Rotation manually. The coordinate system follows the Element local Coordinate System.
Acceptance Criteria (Current Deform./Yield Deform.)
Enter the target performance indices for the structure in terms of ductility (Total Deformation/Yield Deformation). The values outlined in FEMA-273 are used as the reference values. Only positive values are entered if the case is symmetrical.
Note
The legend identifying the status of hinge formation reflects the Acceptance Criteria after pushover analysis is completed. Select Hinge Status in Type of Display in Deformed Shape to observe the status of hinge formation by incremental steps.
Initial Stiffness
6EI/L, 3EI/L, 2EI/L : It is activated when Definition is defined as Moment - Rotation (M-θ).
User : Defined by the user
Elastic Stiffness：Elastic stiffness is used for the initial stiffness.
The Yield Surface Properties... Button
The Yield Surface Properties button enables us to define the interaction of axial force and bending moments where P-M-M in Status Determination of interaction type is selected.
Following definitions are required for Auto-Calculation.
2. Material and section properties defined from the standards
3. Rebar data for RC members
Value Type of I-End & J-End option is activated when the hinge type is defined as Moment-Rotation (M-Θ) or Moment-Curvature (M-φ Lumped) and User Input option is selected. The asymmetrical yield strengths between I-end and J-end are automatically reflected when input method is set to Auto-Calculation.
In Gen, the limit values are set by the total rotation not plastic rotation. So, 1.0*theta_y is added to limit state of code in Gen. This is for convenience of evaluation.
The legend identifying the status of hinge formation reflects the Compliance Criteria after pushover analysis is completed.
Input Method
User : All the input data are user-defined parameters.
Auto : The corresponding yield strength is automatically calculated based on the design code.
Value Type of I-End & J-End
Symmetric : Select if rebar arrangement between i-end and j-end are symmetrical.
Asymmetric : Select if rebar arrangement between i-end and j-end are asymmetrical.
Note
Value Type of I-End & J-End option is activated when the hinge type is defined as Moment-Rotation (M-Θ) or Moment-Curvature (M-φ Lumped) and User Input option is selected. The asymmetrical yield strengths between I-end and J-end are automatically reflected when input method is set to Auto-Calculation.
Type (Y-Axis, Z-Axis)
Symmetric : Select if the hinge properties in Y-axis and Z-axis are symmetrical.
Asymmetric : Select if the hinge properties in Y-axis and Z-axis are asymmetrical.
Component Properties
Define the skeleton curve and initial stiffness, etc for the rotation about y-axis and z-axis.
Type (Plus, Minus)
Symmetric : Select if the hinge properties in the positive and negative moment are symmetrical.
Asymmetric : Select if the hinge properties in the positive and negative moment are asymmetrical.
Yield Strengths
Yield strength about y-axis and z-axis are automatically calculated using the section information if Input Method is set to Auto. Or the user may enter the values of Yield Moment manually if Input Method is set to User.
Interpolation Method : My-Mz
PM interaction curve is interpolated by the Bresler's Load Contour Method. The curve may be of elliptic, linear or user-defined shape. The values of Alpha, 1 and 2 represent linear and elliptic shapes respectively.
Note
If the User defines the interpolation method, the bi-axial moment is formulated by the Bresler's Load Contour Method. In a 3-dimentional interaction diagram, the curve on a Mx-My plane passing a given Pn is represented by the expression
If is assumed, the expression becomes,
In general, retains a value in the range of 1.0-2.0 in a rectangular section. If
is set at 1.0, the curve becomes a straight line and as such it produces the most conservative design. The value of 1.5 may result in a close approximation.
Shape of the 1st and 2nd P-M Interaction Curves
Yield surface about strong and weak axes can be checked by table or graph.
Show Value : Click to display the applied forces and moments in analysis.
Note
1. RC Trilinear
2. RC Bilinear, FEMA, EC8
3. Steel Trilinear
4. Steel Bilinear, FEMA, EC8
Input Method
Auto-Calculation : The corresponding yield strength is automatically calculated based on the design code.
Note
Following definitions are required for Auto-Calculation.
1. Design Code
2. Material and section properties defined from the standards
3. Rebar data for RC members
User Input : All the input data are user-defined parameters.
Value Type of I-End & J-End
Symmetric : Select if rebar arrangement between i-end and j-end are symmetrical.
Asymmetric : Select if rebar arrangement between i-end and j-end are asymmetrical.
Note
Value Type of I-End & J-End option is activated when the hinge type is defined as Moment-Rotation (M-Θ) or Moment-Curvature (M-φ Lumped) and User Input option is selected. The asymmetrical yield strengths between I-end and J-end are automatically reflected when input method is set to Auto-Calculation.
Type
Symmetric : Select if the hinge properties are symmetric in the positive and negative directions.
Asymmetric : Select if the hinge properties are asymmetric in the positive and negative directions.
Yield Strength (MY)
The values are automatically calculated using the section information if Input Method is set to Auto-Calculation. Or the user may enter the values of Yield Moment manually if Input Method is set to User-Input. The coordinate system follows the Element local Coordinate System.
Yield Rotation (DY)
User Defined : The values are automatically calculated using the section information if this option is checked off. Or the user may enter the values of Yield Rotation manually. The coordinate system follows the Element local Coordinate System.
Acceptance Criteria (Current Deform./Yield Deform.)
Enter the target performance indices for the structure in terms of ductility (Total Deformation/Yield Deformation). The values outlined in FEMA-273 are used as the reference values. Only positive values are entered if the case is symmetrical.
Note
The legend identifying the status of hinge formation reflects the Acceptance Criteria after pushover analysis is completed. Select Hinge Status in Type of Display in Deformed Shape to observe the status of hinge formation by incremental steps.
Initial Stiffness
6EI/L, 3EI/L, 2EI/L : It is activated when Definition is defined as Moment - Rotation (M-θ).
User : Defined by the user
Elastic Stiffness：Elastic stiffness is used for the initial stiffness.
Note 3
1. When Definition is Moment-Rotation (M-θ) :
2. When Definition is Moment-Curvature (M-φ Lumped, Distributed)
3. When Element Type is Truss (Fx component):
4. When Element Type is General Link
Note 4
The initial stiffness used in inelastic analysis is either selected or entered by the user.
The selection of initial stiffness is founded on the premises of the longitudinal distribution of bending moment. If the bending moments, which are assumed to be linearly distributed, are the same in magnitude with opposite signs at both ends, select 6EI/L. If one end is 0, select 3EI/L. If the magnitudes and the signs are identical, select 2EI/L.
6EI/L , 3EI/L, 2EI/L : Provided that the inelastic hinge is of a lumped type for the bending moment component, the initial stiffness is selected on the basis of the longitudinal distribution of bending moment. This cannot be selected in case of Distributed Type and Spring Type.
6EI/L : when end values of linearly distributed bending moment are identical in magnitude but in opposite directions
3EI/L : when one end is 0
2EI/L : when the magnitudes and signs of end values are identical
User : the user directly enters the initial stiffness if the Input Type is Strength - Stiffness Reduction Ratio.
Elastic Stiffness : elastic stiffness of a member is used as the initial stiffness for inelastic analysis.
Skeleton Curve : when Strength - Yield Displacement is selected for the Input Type, the ratio of the user specified yield strength and yield displacement is used as the initial stiffness.
Masonry Properties
In the structural model, masonry spandrels may be taken into account as coupling beams between two wall elements. This assumption implies that they should regularly bonded to the adjoining walls and connected both to the floor tie beam and to the lintel below. If the structural model takes into account the coupling beams, a frame analysis may be used for the determination of the action effects on the vertical and horizontal structural elements.
Building Type : Flexural capacity and shear resistance of masonry pier depends on the type of building as shown in the table below.
Following data are required to calculate the resistance of masonry pier.
Compressive Strength (fm)
Shear Strength (t0)
Vertical Stress Distribution Coefficient (k)
Note 1
How to calculate the resistance
- Axial resistance :
- Shear resistance :
- Flexural resistance :
Note 2
Calculated resistance can be checked in Design > Pushover Analysis > Pushover Hinge Result Table > Beam Summary table.
Note 3
Element Local axis of masonry wall pier
In-plane horizontal direction and transverse direction of the wall pier should coincide with the local z-axis and local y-axis of the element, respectively as shown in the figure below, which directly affects the resistance of the wall pier. Also, the program calculates hinge properties (My component) on the assumption above.
Following data are required to calculate the resistance of masonry spandrel.
Horizontal Compressive Strength (fhd)
Shear Strength in absence of Vertical Loads (fvk0)
Hp
Note 1
How to calculate the resistance
- Axial resistance:
- Shear resistance in regular/irregular type
The calculation for shear resistance is as follows.
- Flexural resistance:
Note 2
Calculated resistance can be checked in Design > Pushover Analysis > Pushover Hinge Result Table > Beam Summary table.