Every structure undergoes changes over a period; some occur over short time periods while others take a long time. While time is always an independent variable in play, it is not necessary to consider it in analyzing all systems. But how do we identify when time may be ignored (e.g., static and quasi-static analyses) and when is it necessary to be considered? In this Ansys Innovation Course on “Time Domain Analysis,” we will introduce the governing equations of motion and discuss when and how an independent time variable is important in studying a structure’s mechanical response. We will discuss what factors introduce time dependency and when the analysis may be idealized as a static analysis. Students will learn the importance of considering inertial effects in an analysis and how they may change a system’s mechanical behavior.