Analysis

SPACE GASS uses the well documented stiffness method combined with SG-X, Paradise and Wavefront equation solvers to model the elastic behaviour of structures. It is capable of performing seven types of analysis, as follows.

 

• Linear (1st order) static analysis

• Non-linear (2nd order) static analysis

• Buckling analysis

• Dynamic frequency analysis

• Spectral response analysis

• Harmonic response analysis

• Transient (time-history) response analysis

• Displacement control analysis (SG-X only)

 

The SPACE GASS analysis modules can accurately deal with semi-rigid joints, elastic supports, master-slave constraints, offsets, tension/compression-only members, and cable members (static and buckling analysis only).

 

Geometric nonlinear plates/shells are now supported in the static analysis solver, and plate/shell buckling is now supported in the buckling analysis solver. In early versions plates/shells only behaved linearly.

 

Material nonlinear plates/shells are now supported in the SG-X solver.

 

Although the Wavefront solver is not highly sensitive to badly numbered structures, an optimizer which automatically minimizes the frontwidth is also available with SPACE GASS. The optimizer increases the analysis speed and reduces its memory requirements, and means that both the node, member and plate numbering sequences are incidental to the program.

 

The Paradise solver uses a compressed stiffness matrix which does not require any optimization.

 

The SG-X solver option is a modern, high performance, multithreaded finite element analysis engine developed from the ground up in C++. SG-X is designed to deliver substantially faster solve times, improved reliability, and full coverage of all analysis capabilities provided by the other solvers. 

 

Displacement control analysis is now supported in the SG-X solver.

 

 

^*For Spectral Response, Harmonic Response, and Transient (Time History) Response, SG-X currently utilises the same analysis facility and engine as the existing solvers. Dedicated modern C++ engines for these three analysis response types are under development and will be integrated into SG-X in a future release.

 

SPACE GASS has been dimensioned dynamically. This means that during the analysis phase SPACE GASS automatically adjusts its memory requirements according to the size of the job. If the available memory in your computer is enough to solve the structure entirely in memory then the analysis phase will be extremely fast. If you run out of memory during an analysis then some of the analysis data will be automatically written to disk and the analysis phase will not be quite as fast. You should aim to have as much of the data as possible held in memory during the analysis by minimizing the bandwidth/frontwidth or by increasing the memory capacity of your computer.

 

In this manual "plates" and "shells" are used interchangeably. The "plate" elements in SPACE GASS are actually "shells" because they consider all in-plane and out-of-plane actions, however they have previously been referred to in SPACE GASS and its documentation as simply "plates".

 

For information on running multiple analysis tasks in batch mode refer to "Batch processing".