Push Over Analysis Parameters

Use this dialog to set up Pushover Analysis parameters for a dynamic case.

Access

1. Ensure that a modal analysis has already been defined.
2. Click Analysis Analysis Types New.
3. Select Push over in the Analysis Type dialog, and then click OK.

 

Case

The name of the load case.

Parameters

• Node number - The number of a structure node belonging to the structure roof (see the figure below).
  
• Direction - Direction of an external factor affecting the structure in the global coordinate system.
• Maximum displacement - Maximum displacement in the selected structure node.

Method of load definition

• According to unit acceleration in the given direction - Determines a displacement vector during the pushover analysis.
• User-defined.

Note: The According to unit acceleration in the given direction option uses the following algorithm.

1. Calculation of the vector , where K, M - stiffness matrix and mass matrix, respectively, I_dir - unit direction vector; Φ _dir - push mode vector.
2. Normalization: , where .
3. Definition of mass participation factor: Γ _dir = (M I_dir , F _dir).
4. Definition of lateral forces as: F_dir = γ_dir M Φ _dir , where γ_dir is a scalar multiplier.

The right-hand side of the equation system presented in point 1 can be defined with a static load case that will make up a set of forces applied to the structure. The algorithm of calculation of lateral forces (points 2, 3, 4) is identical to that described above.

Geometric nonlinearity

• P-Delta - Select this option to consider P-Delta effects during the analysis.
• Large displacements - Select this option to take into account large displacements and/or rotations during the analysis.
• Nonlinear analysis parameters - Opens a dialog which allows you to set up the options of the nonlinear analysis.

See also:

Pushover analysis description