Pushover analysis parameters are accessed by doing any of the following.
- Click New on the Analysis Types dialog, select Push over, and click OK in the New Case Definition dialog.
- Select Push over and click OK in the Change Analysis Type dialog or select the push over analysis case and click Parameters in the Analysis Types dialog.
The resulting dialog defines push over analysis parameters for a load case defined for a structure.
The following parameters may be determined in the above dialog box:
Case - The name of a load case
Node number - 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.
Select According to unit acceleration in the given direction to determine a displacement vector during the pushover analysis. The following algorithm is used.
- Calculation of the vector
, where K, M - stiffness matrix and mass matrix, respectively, Idir - unit direction vector; Φ dir - push mode vector. - Normalization:
, where 
. - Definition of mass participation factor: Γ dir = (M Idir , F dir).
- Definition of lateral forces as: Fdir = γdir M Φ dir , where γdir 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.
Moreover, the following options of non-linear analysis are available.
Non-linear analysis - Influence of the axial force.
P-Delta analysis - Influence of the quadratic components of the equation.
Clicking Parameters opens the Nonlinear Analysis Algorithm Options dialog which determines the analysis parameters of methods applied to solve an equation system.
See also: