The potential and limitations of Time History Analysis includes the following.
- The same structure and load types are available as in the case of linear statics.
- The function of load variability may be defined for an arbitrary static load case with the exception of the moving load case. In order to model a dynamic impact of a moving load, successive vehicle positions should be defined in separate load cases and use the time functions with the phase shift corresponding to the vehicle movement.
- Additional modeling options available in the linear static analysis can be used (such as releases, elastic connections, rigid links, and others).
- Case components may be used in combinations after generating an additional load case containing the results of analysis for a given component.
- It allows adopting initial displacements from a selected load case, assuming simultaneously zero values of initial velocities and accelerations.
- It is solved only by the means of the modal decomposition method, which requires that modal analysis be carried out first.
- Only one time function may be used to determine time variability of loads of a given load case. It is possible, however, to add time functions.
There are a considerable number of facilitating options in the time history analysis.
- A graphical interface for introducing data, accompanied by the visualization of time function course.
- The possibility of reading a time function from and saving it to an easily editable text file.
- Scaling and phase shift of time functions.
- Calculation notes with all the pertaining data.
- The possibility of using the results for time history case components in combinations
- Perfected graphical presentation of the resultant values in diagrams. View diagram comparisons of several arbitrarily selected quantities in one viewer, with time function course displayed.
- Diagrams of a new resultant value - foundations shearing forces.
In order to obtain satisfactory results for time history analysis cases, it is required to carry out iterative analysis with multiple calculations for different case parameters. Modal analysis needs to be carried out again. In the case of a large-scale structure, the modal analysis itself may be time-consuming, as will the time history analysis. Therefore, it is necessary to select cases for calculations or at least to mark the modal analysis as calculated. This may also be useful in the case of seismic analysis.