Modal Time History Analysis
Use modal time history analysis when the variation of each load with time is known explicitly, and you are interested in the response as a function of time.
Typical loads include:
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shock (or pulse) loads
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general time-varying loads (periodic or non-periodic)
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uniform base motion (displacement, velocity, or acceleration applied to all supports)
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support motions (displacement, velocity, or acceleration applied to selected supports non-uniformly)
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initial conditions (a finite displacement, velocity, or acceleration applied to a part or the whole model at time t =0)
The solution of the equations of motion for multi degree-of-freedom systems incorporates Modal analysis techniques.
The solution's accuracy can improve by using a smaller time step.
After running the study, you can view displacements, stresses, strains, reaction forces, etc. at different time steps, or you can graph results at specified locations versus time. If no locations are specified in Result Options, results at all nodes are saved.
Damping Effects
Modal, Rayleigh, composite modal, and concentrated dampers are available for modal time history analysis.
Related Topic
Loads and Result Options for Dynamic Analysis
Solution Accuracy for Dynamic Analysis
When to Use Dynamic Analysis
Damping Effects
Performing Linear Dynamic Analysis