For Abaqus, two Analysis Types are supported: Static and Natural Frequency Extraction.
For Static analysis, the Initial time increment, Time period of each step, Minimum and Maximum time increments need to be specified.
The Natural Frequency Extraction procedure performs eigenvalue extraction to calculate natural frequencies and the corresponding mode shape of a system. It includes the initial stress and load stiffness effect, and is a linear perturbation procedure. The following parameters pertain to the Natural Frequency Extraction type of analysis.
- Eigensolver
There are two types of Eigensolvers, Lanczos and Subspace Iteration. Lanczos is faster when you must extract a large number of eigen modes, such as for airframes, piping systems and building skeletons. The subspace iteration method may be faster when only a few (less than 20) eigen modes are needed.
- Number of Modes to Extract
Specify the number of modes to be extracted.
- Beginning (minimum) and Ending (maximum) Frequency
Specify the beginning and ending frequencies.
- Shift point
Specify the shift point.
- Maximum iterations
Specify the maximum number of iterations.
- Normalized By
Specify whether it is to be normalized by Mass Matrix or Large Displacement.
The following parameters pertain to both types of analysis.
- Maximum increments
Specify the maximum number of increments.
- Step amplitude
Specify whether to use Stepped or Ramped amplitude.
- Include large displacement effect
Specify whether to include the effect of large displacement.