The Time-Dependent Modal () study and study step are used to compute the dynamic structural deformation of an object subject to a transient force.

The study consists of two study steps: one Eigenfrequency study step for computing the eigenfrequencies and eigenmodes of the structure, and a second Time-Dependent Modal study step for computing the modal response. In the modal superposition analysis, the deformation of the structure is represented by a linear combination of the structure’s eigenmodes. This means that the frequency content of the loads is limited by the frequencies of the computed eigenmodes. All loads are assumed to have the same variation with time. A Time-Dependent Modal study usually results in a faster computation than a direct solution using the Time Dependent study.

Selecting a Time-Dependent Modal study step gives a Time-Dependent Modal study step with a Modal Solver. Use it for performing transient response analyses. The settings are the same as for the Time Dependent study step for the sections that they share (the Time Dependent study step includes some additional settings). Also see The Relationship Between Study Steps and Solver Configurations.