Analysis Wizard : Static P-delta

Definition

P-delta case

For a static P-delta analysis the user must specify the basis for the geometric stiffness The options are:

• Each analysis case defining its own geometric stiffness
• Load case definition
• Result case

The basis on which the geometric stiffness is calculated. The first option requires a separate solution for each analysis case as a new geometric (or differential) stiffness matrix is required for each analysis case, based on the load in that case. The second option allows a load definition (e.g. 1.2L1 + 1.2L2) to be specified. In this case GSA first analyses the structure under this load and generates a geometric stiffness from the resulting forces/moments. In the third an analysis case or combination case is specified and the geometric stiffness is constructed from the results in this analysis case. The combination cases must be a simple combination (only one permutation).