D2.B.2 Analysis Methodology

Either the elastic or dynamic analysis methods may be used to obtain the forces and moments for design as per AS 4100 section 4.4. Analysis is done for the specified primary and repeat loading conditions. Therefore, it is your responsibility to enter all necessary loads and load combination factors for design in accordance with the AS/NZS 1170 Series or other relevant design codes. You are allowed complete flexibility in providing loading specifications and using appropriate load factors to create necessary loading situations. Depending upon the analysis requirements, regular stiffness analysis or P-Delta analysis may be specified. Dynamic analysis may also be performed and the results combined with static analysis results.

Note: Plastic analysis and design in accordance with AS 4100 section 4.5 is not implemented in STAAD.Pro.

D2.B.2.1 Elastic Analysis

Two types of elastic analysis can be performed using STAAD.Pro in accordance with AS 4100:

First Order Linear, Elastic Analysis - used to perform a regular elastic stiffness analysis as per AS 4100 4.4.2.1. Refer to TR.37.1 Linear Elastic Analysis for additional details on this feature.
Second Order PDelta Linear, Elastic Analysis - Depending on the type of structure, a PDelta analysis may be required in order to capture second-order effects as per AS 4100 4.4.1.2. Second-order effects can be captured in STAAD.Pro by performing a PDelta second-order elastic analysis as per AS 4100 Appendix E. Refer to TR.37.2 P-Delta Analysis Options for additional details on this feature.

Note: Moment amplification as per AS 4100 clause 4.4.2 is not considered.

Tip: In order to correctly capture second-order effects for combination load cases using a PDelta Analysis, the Repeat Load feature must be used. Second-order effects will not be correctly evaluated if the Load Combination feature is used. Load Combinations are combinations of results where Repeat Loads instruct the program to perform the analysis on the combined load actions. Refer to TR.32.11 Repeat Load Specification for additional details on using Repeat Loads.

D2.B.2.2 Dynamic Analysis

Dynamic analysis may also be performed and the results combined with static analysis results. Refer TR.32.10 Dynamic Loading Specification for further information on Dynamic Loading and Analysis features.