## Function

- Enter the load cases and the control parameters for iterations used in the P-Delta analysis of a structure.
- When considering the P-Delta effect in both static and dynamic analysis processes, you need to specify the load conditions to be considered in the formation of the geometric stiffness matrix and provide additional inputs for convergence, such as the number of iterations required and convergence tolerance. To do this, you can navigate to the [Analysis] tab, then go to the [Analysis Control] group, and use the P-Delta Analysis Control option.
- midas Civil permits P-Delta analysis for only the structures consisted of beam and truss elements.

In P-Delta analysis, internal moments along a beam element between the two nodes can be obtained from the relative displacements of internal points to the two nodes multiplied by the axial force. V 6.3.0 automatically generates internal nodes and finds internal displacements to calculate the P-Delta moments along the beam elements.

## Call

From the main menu, select **[Analysis] tab > [Analysis Control] group > [P-Delta]**

## Input

**To enter a new or additional load case**

Enter the Load Case and Scale Factor, then click **Add**.

**To modify the scale factor for a previously entered load case**

Select the load case, modify the Scale Factor, and click **Modify**.

**To delete a previously entered load case**

Select the load case to be deleted from the load case list at the bottom of the dialog box and click **Delete**.

P-Delta Analysis and Buckling Analysis may not be used simultaneously. The use of P-Delta Analysis is limited to truss and beam elements.

To delete all the entered data, click **Remove P-Delta Analysis Data**.

### Control Parameters

**Number of Iteration**

Enter the number of iterations for the P-Delta analysis

**Convergence Tolerance**

Enter the convergence tolerance

### P-Delta Combinations

Select the loads that will be applied to determine the geometric stiffness matrix used in the P-Delta analysis. Enter different Load Cases with the corresponding Scale Factors.

Select the dead loads (self-weight, dead load, etc.) generally acting on the structures.